diff --git a/app/Booking.php b/app/Booking.php
index c7730ca..8865128 100644
--- a/app/Booking.php
+++ b/app/Booking.php
@@ -6,50 +6,92 @@ use Illuminate\Database\Eloquent\Model;
 
 class Booking extends Model
 {
-    public function amount()
-    {
-        return $this->subBookings()->sum('amount');
-    }
-
-    public function signedAmount()
-    {
-        return $this->subBookings()->withSignedAmount()->get()
-                    ->sum('signedAmount');
-    }
+    /**************************************************************************
+     * DIRECT RELATIONS                                                       *
+     **************************************************************************/
 
+    /**
+     * Return all sub-bookings which belong to the booking.
+     *
+     * @return Illuminate\Database\Eloquent\Relations\HasMany
+     */
     public function subBookings()
     {
         return $this->hasMany('App\SubBooking');
     }
 
+    /**************************************************************************
+     * INDIRECT RELATIONS                                                     *
+     **************************************************************************/
+
+    /**
+     * Get the project to which the booking belongs. If the booking consists of
+     * more than one sub-booking, null is returned.
+     *
+     * @return App\Project
+     */
+    public function project()
+    {
+        if ($this->isSimple()) {
+            return $this->subBookings->first()->project;
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the account type of the booking. If the booking consists of more than
+     * one sub-booking, null is returned.
+     *
+     * @return App\AccountType
+     */
+    public function accountType()
+    {
+        if ($this->isSimple()) {
+            return $this->subBookings->first()->accountType;
+        }
+
+        return null;
+    }
+
+    /**************************************************************************
+     * INDIRECT PROPERTIES                                                    *
+     **************************************************************************/
+
+    /**
+     * Get the (unsigned) amount of all sub-bookings.
+     *
+     * @return float
+     */
+    public function amount()
+    {
+        return $this->subBookings->sum('amount');
+    }
+
+    /**
+     * Return the sum of all signed amounts of all sub-bookings related to the
+     * booking.
+     *
+     * @return float
+     */
+    public function signedAmount()
+    {
+        $sum = 0;
+
+        foreach ($this->subBookings as $subBooking) {
+          $sum += $subBooking->signedAmount();
+        }
+
+        return $sum;
+    }
+
     /**
      * Return true, if the booking consists only of one sub-booking.
-     * NOTICE: The book instance has to be loaded with the
-     * ->withCount('subBookings') method to be able to access the comments
-     * count.
      *
      * @return boolean
      */
     public function isSimple()
     {
-        return $this->sub_bookings_count === 1;
-    }
-
-    public function project()
-    {
-        if ($this->isSimple()) {
-            return $this->subBookings()->first()->project();
-        }
-
-        return null;
-    }
-    
-    public function accountType()
-    {
-        if ($this->isSimple()) {
-            return $this->subBookings()->first()->accountType();
-        }
-
-        return null;
+        return $this->subBookings->count() === 1;
     }
 }
diff --git a/app/Http/Controllers/BookingsController.php b/app/Http/Controllers/BookingsController.php
index 74fd685..d3b2e14 100644
--- a/app/Http/Controllers/BookingsController.php
+++ b/app/Http/Controllers/BookingsController.php
@@ -16,9 +16,10 @@ class BookingsController extends Controller
      */
     public function index($year)
     {
-        $bookings = Booking::whereYear('date', '=', $year)
+        $bookings = Booking::with('subBookings.accountType.accountClass.ioType',
+                                  'subBookings.project')
+                           ->whereYear('date', '=', $year)
                            ->orderBy('date')
-                           ->withCount('subBookings')
                            ->get()
                            ->groupBy(function($item) {
                                return Carbon::parse($item->date)->format('n');
diff --git a/app/SubBooking.php b/app/SubBooking.php
index b8b4b6d..a3f30b7 100644
--- a/app/SubBooking.php
+++ b/app/SubBooking.php
@@ -8,9 +8,77 @@ use Carbon\Carbon;
 
 class SubBooking extends Model
 {
+    /**************************************************************************
+     * DIRECT RELATIONS                                                       *
+     **************************************************************************/
+    
+    /*
+     * Get the booking which contains the sub-booking.
+     *
+     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function booking() {
+        return $this->belongsTo('\App\Booking', 'booking_id');
+    }
+    
+    /*
+     * Get the person-target related to the sub-booking. 
+     *
+     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function personTarget()
+    {
+        return $this->belongsTo('App\PersonTarget', 'person_target_id');
+    }
+
+    /*
+     * Get the project related to the sub-booking.
+     *
+     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function project()
+    {
+        return $this->belongsTo('App\Project', 'project_id');
+    }
+    
+    /*
+     * Get the account type related to the sub-booking. 
+     *
+     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function accountType() 
+    {
+        return $this->belongsTo('App\AccountType', 'account_type_id');
+    }
+
+    /**************************************************************************
+     * INDIRECT PROPERTIES                                                    *
+     **************************************************************************/
+
+    /*
+     * Get the booking date for a sub-booking.
+     *
+     * @return string
+     */
+    public function date()
+    {
+        return $this->booking->date;
+    }
+    
+    /*
+     * Get the IO-type of the sub-booking.
+     *
+     * @return 
+     */
+    public function ioType()
+    {
+        return $this->accountType->accountClass->ioType;
+    }
+
+    
     public function signedAmount()
     {
-        return $this->ioType->factor * $this->amount;
+        return $this->ioType()->factor * $this->amount;
     }
 
     /**************************************************************************
@@ -172,17 +240,6 @@ class SubBooking extends Model
         return $query->join('bookings', 'bookings.id', '=', 'sub_bookings.booking_id');
     }
 
-    /**
-     * Add a signed amount property to the table.
-     *
-     * @return Illuminate\Database\Eloquent\Builder
-     */ 
-    public function scopeWithSignedAmount($query)
-    {
-        return $query->joinAccountBranch()
-                     ->addSelect(DB::raw('sub_bookings.*, (i_o_types.factor * sub_bookings.amount) as signedAmount'));
-    }
-
     /**
      * Join the tables 'i_o_types', 'account_classes' and 'account_types' into
      * the query.
@@ -195,79 +252,4 @@ class SubBooking extends Model
                      ->join('account_classes', 'account_classes.id', '=', 'account_types.account_class_id')
                      ->join('i_o_types', 'i_o_types.id', '=', 'account_classes.io_type_id');
     }
-
-    /**************************************************************************
-     * BOOKINGS                                                               *
-     **************************************************************************/
-
-    /*
-     * Get the booking which contains the sub-booking.
-     *
-     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
-     */
-    public function booking() {
-        return $this->belongsTo('\App\Booking', 'booking_id');
-    }
-
-    /*
-     * Get the booking date for a sub-booking.
-     *
-     * @return string
-     */
-    public function date()
-    {
-        return $this->booking->date;
-    }
-    
-    /**************************************************************************
-     * ACCOUNT TYPES                                                          *
-     **************************************************************************/
-    
-    /*
-     * Get the account type related to the sub-booking. 
-     *
-     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
-     */
-    public function accountType() 
-    {
-        return $this->belongsTo('App\AccountType', 'account_type_id');
-    }
-
-    /*
-     * Get the IO-type of the sub-booking.
-     *
-     * @return 
-     */
-    public function ioType()
-    {
-        return $this->accountType->ioType();
-    }
-
-    /**************************************************************************
-     * PERSON TARGETS                                                         *
-     **************************************************************************/
-    
-    /*
-     * Get the person-target related to the sub-booking. 
-     *
-     * @return Illuminate\Database\Eloquent\Relations\BelongsTo
-     */
-    public function personTarget()
-    {
-        return $this->belongsTo('App\PersonTarget', 'person_target_id');
-    }
-
-    /**************************************************************************
-     * PROJECTS                                                               *
-     **************************************************************************/
-    
-    /*
-     * Get the project related to the sub-booking.
-     *
-     * @return Illuminate\Database\Eloquent\Relations\belongsTo
-     */
-    public function project()
-    {
-        return $this->belongsTo('App\Project', 'project_id');
-    }
 }
diff --git a/resources/views/bookings/index.blade.php b/resources/views/bookings/index.blade.php
index 8d4c7e6..1c2f4d2 100644
--- a/resources/views/bookings/index.blade.php
+++ b/resources/views/bookings/index.blade.php
@@ -60,17 +60,18 @@
                     </td>
                     <td>
                         @if ($booking->isSimple())
-                            {{ $booking->accountType->name }}
+                            {{ $booking->accountType()->number . ' - ' .
+                               $booking->accountType()->name }}
                         @endif
                     </td>
                     <td>
                         @if ($booking->isSimple())
-                            {{ $booking->project->name }}
+                            {{ $booking->project()->name }}
                         @endif
                     </td>
                 </tr>
                 @if (!$booking->isSimple())
-                    @foreach ($booking->subBookings()->withSignedAmount()->get() as $subBooking)
+                    @foreach ($booking->subBookings() as $subBooking)
                         <tr>
                             <td>+</td>
                             <td></td>
@@ -78,17 +79,18 @@
                             <td>{{ $subBooking->reference }}</td>
                             <td></td>
                             <td align='right'>
-                                @if ($subBooking->signedAmount < 0)
+                                @if ($subBooking->signedAmount() < 0)
                                     {{ formatAmount($subBooking->signedAmount) }}
                                 @endif
                             </td>
                             <td align='right'>
-                                @if ($subBooking->signedAmount >= 0)
+                                @if ($subBooking->signedAmount() >= 0)
                                     {{ formatAmount($subBooking->signedAmount) }}
                                 @endif
                             </td>
                             <td>
-                                {{ $subBooking->accountType->name }}
+                                {{ $subBooking->accountType->number . ' - ' .
+                                   $subBooking->accountType->name }}
                             </td>
                             <td>
                                 {{ $subBooking->project->name }}
@@ -120,10 +122,10 @@
                 </td>
                 <td>Saldo</td>
                 <td></td>
-                <td></td>
                 <td>{{ formatAmount($sums[$month]['balance']) }}</td>
                 <td></td>
                 <td></td>
+                <td></td>
             </tr>
             <tr>
                 @for ($i = 0; $i < 9; $i++)