diff --git a/Smartway.UiComponent.Sample/DummyArticle.cs b/Smartway.UiComponent.Sample/DummyArticle.cs
index 53d3407..cd5d3ee 100644
--- a/Smartway.UiComponent.Sample/DummyArticle.cs
+++ b/Smartway.UiComponent.Sample/DummyArticle.cs
@@ -25,7 +25,7 @@ public ICommand NavigationCommand
 
         public object NavigationParameter { get; set; }
         public string Status { get; set; }
-        public DateTime? ShortageAt
+        public DateTime? OnShortageSince
         {
             get => DateTime.Today;
             set => throw new NotImplementedException();
diff --git a/Smartway.UiComponent.Sample/SectionSheet/ViewModels/SectionSheetSampleViewModel.cs b/Smartway.UiComponent.Sample/SectionSheet/ViewModels/SectionSheetSampleViewModel.cs
index f866b63..01b5ada 100644
--- a/Smartway.UiComponent.Sample/SectionSheet/ViewModels/SectionSheetSampleViewModel.cs
+++ b/Smartway.UiComponent.Sample/SectionSheet/ViewModels/SectionSheetSampleViewModel.cs
@@ -1,10 +1,10 @@
-using System.Collections.Generic;
+using System.Collections.ObjectModel;
 
 namespace Smartway.UiComponent.Sample.SectionSheet.ViewModels
 {
     class SectionSheetSampleViewModel: ViewModel
     {
-        public List<object> Articles => new List<object>
+        public ObservableCollection<object> Articles => new ObservableCollection<object>
         {
             new DummyArticle
             {
diff --git a/Smartway.UiComponent/CardLists/ArticleCardList.xaml b/Smartway.UiComponent/CardLists/ArticleCardList.xaml
index faa3264..09a5bcd 100644
--- a/Smartway.UiComponent/CardLists/ArticleCardList.xaml
+++ b/Smartway.UiComponent/CardLists/ArticleCardList.xaml
@@ -19,7 +19,7 @@
                             Gencode="{Binding Gencode}"
                             NavigationCommand="{Binding NavigationCommand}"
                             NavigationParameter="{Binding NavigationParameter}"
-                            ShortageAt="{Binding ShortageAt}"
+                            OnShortageSince="{Binding OnShortageSince}"
                         />
                     </StackLayout>
                 </DataTemplate>
diff --git a/Smartway.UiComponent/CardLists/ExpanderCardList.xaml.cs b/Smartway.UiComponent/CardLists/ExpanderCardList.xaml.cs
index 1f00383..a30a9b8 100644
--- a/Smartway.UiComponent/CardLists/ExpanderCardList.xaml.cs
+++ b/Smartway.UiComponent/CardLists/ExpanderCardList.xaml.cs
@@ -158,7 +158,7 @@ private void SaveAction(NotifyCollectionChangedEventArgs e)
 
         private async Task OnExpanderClick()
         {
-            ExpandCommand.Execute(null);
+            ExpandCommand?.Execute(null);
             if (ExpanderState != ExpanderState.Expanding)
                 return;
 
diff --git a/Smartway.UiComponent/Cards/ArticleCard.xaml b/Smartway.UiComponent/Cards/ArticleCard.xaml
index f762531..596bdad 100644
--- a/Smartway.UiComponent/Cards/ArticleCard.xaml
+++ b/Smartway.UiComponent/Cards/ArticleCard.xaml
@@ -66,8 +66,8 @@
                     <Label
                         Style="{StaticResource RegularGencodeText}"
                         TextColor="Black"
-                        Text="{Binding Source={Reference Self}, Path=ShortageAt, StringFormat='Rupture depuis le {0:dd/MM/yyyy}'}"
-                        IsVisible="{Binding Source={Reference Self}, Path=DisplayShortageAt}"
+                        Text="{Binding Source={Reference Self}, Path=OnShortageSince, StringFormat='Rupture depuis le {0:dd/MM/yyyy}'}"
+                        IsVisible="{Binding Source={Reference Self}, Path=DisplayOnShortageSince}"
                     />
                     <indicators:Status IsVisible="False" HorizontalOptions="StartAndExpand">
                         <indicators:Status.Triggers>
diff --git a/Smartway.UiComponent/Cards/ArticleCard.xaml.cs b/Smartway.UiComponent/Cards/ArticleCard.xaml.cs
index aac3f9a..ca9a2ef 100644
--- a/Smartway.UiComponent/Cards/ArticleCard.xaml.cs
+++ b/Smartway.UiComponent/Cards/ArticleCard.xaml.cs
@@ -15,7 +15,7 @@ public partial class ArticleCard
         public static readonly BindableProperty PriceProperty = BindableProperty.Create(nameof(Price), typeof(string), typeof(ArticleCard));
         public static readonly BindableProperty NavigationCommandProperty = BindableProperty.Create(nameof(NavigationCommand), typeof(ICommand), typeof(ArticleCard));
         public static readonly BindableProperty NavigationParameterProperty = BindableProperty.Create(nameof(NavigationParameter), typeof(object), typeof(ArticleCard));
-        public static readonly BindableProperty ShortageAtProperty = BindableProperty.Create(nameof(ShortageAt), typeof(DateTime?), typeof(ArticleCard), DateTime.Today);
+        public static readonly BindableProperty OnShortageSinceProperty = BindableProperty.Create(nameof(OnShortageSince), typeof(DateTime?), typeof(ArticleCard), DateTime.Today);
         public static readonly BindableProperty StatusProperty = BindableProperty.Create(nameof(Status), typeof(string), typeof(ArticleCard), "Unknown");
 
         public bool IsMultilocation
@@ -42,10 +42,10 @@ public bool IsOnShortage
             set => SetValue(IsOnShortageProperty, value);
         }
 
-        public DateTime? ShortageAt
+        public DateTime? OnShortageSince
         {
-            get => (DateTime?) GetValue(ShortageAtProperty);
-            set => SetValue(ShortageAtProperty, value);
+            get => (DateTime?) GetValue(OnShortageSinceProperty);
+            set => SetValue(OnShortageSinceProperty, value);
         }
 
         public string Price
@@ -72,7 +72,7 @@ public string Status
             set => SetValue(StatusProperty, value);
         }
 
-        public bool DisplayShortageAt => IsOnShortage && ShortageAt != null;
+        public bool DisplayOnShortageSince => IsOnShortage && OnShortageSince != null;
 
         public ArticleCard()
         {