diff --git a/src/ui/tree.c b/src/ui/tree.c
index ac48935..3c93c5f 100644
--- a/src/ui/tree.c
+++ b/src/ui/tree.c
@@ -28,12 +28,49 @@
 #include "../../include/base.h"
 #include "../../include/ui.h"
 
+#include <gtk/gtk.h>
+
+enum
+{
+  COL_FIRST_NAME = 0,
+  COL_LAST_NAME,
+  NUM_COLS
+} ;
+
 GtkListStore *list_store;
 GtkTreeStore *tree_store;
 GtkTreeIter   iter, child;
 
 static void tree_c_printing_test(void);
 
+static GtkTreeModel *
+create_and_fill_model (void)
+{
+  GtkTreeStore  *treestore;
+  GtkTreeIter    toplevel, child;
+
+  treestore = gtk_tree_store_new(NUM_COLS, G_TYPE_STRING, G_TYPE_STRING);
+
+  /* Append a top level row and leave it empty */
+  gtk_tree_store_append(treestore, &toplevel, NULL);
+
+  /* Append a second top level row, and fill it with some data */
+  gtk_tree_store_append(treestore, &toplevel, NULL);
+  gtk_tree_store_set(treestore, &toplevel,
+                     COL_FIRST_NAME, "Joe",
+                     COL_LAST_NAME, "Dalton",
+                     -1);
+
+  /* Append a child to the second top level row, and fill in some data */
+  gtk_tree_store_append(treestore, &child, &toplevel);
+  gtk_tree_store_set(treestore, &child,
+                     COL_FIRST_NAME, "Averell",
+                     COL_LAST_NAME, "Dalton",
+                     -1);
+
+  return GTK_TREE_MODEL(treestore);
+}
+
   /***********************************************************
   *                                                          *
   *  Going through every row in a list store                 *
@@ -130,10 +167,10 @@ tree_c_test(void)
 
 static void tree_c_printing_test(void)
 {
-
     printf("tree_c_printing_test() \
 ---------------------------------------------------------\n\n\
-(https://en.wikibooks.org/wiki/GTK (modulo) 2B_By_Example/Tree_View/Tree_Models)\n\n\
+(https://en.wikibooks.org/wiki/GTK (modulo) 2B_By_Example/Tree_View/Tree_Models)\n\
+(https://en.wikibooks.org/wiki/GTK (modulo) 2B_By_Example/Tree_View/Columns_and_Renderer)\n\n\
 cf. tuto : gtk_list_store_new (2, G_TYPE_STRING, G_TYPE_UINT);  - (cf. line 69)\n\
            creates a new list store with two columns.\n\n\
            gtk_tree_store_new(1, G_TYPE_STRING);  - (cf. line 108)\n\