diff --git a/main/newscorm/resourcelinker.inc.php b/main/newscorm/resourcelinker.inc.php
index 9981f27ab8..6562d3e346 100755
--- a/main/newscorm/resourcelinker.inc.php
+++ b/main/newscorm/resourcelinker.inc.php
@@ -103,16 +103,16 @@ function show_documents($folder)
 	// other tools do not have this feature. This only counts
 	if (is_allowed_to_edit())
 	{
-		$visibility="visibility<>'2'";
+		$visibility="ip.visibility<>'2'";
 	}
 	else
 	{
-		$visibility="visibility='1'";
+		$visibility="ip.visibility='1'";
 	}
 
 	$item_property_table = Database::get_course_table(TABLE_ITEM_PROPERTY);
 	$document_table = Database::get_course_table(TABLE_DOCUMENT);
-	$sql="SELECT * from $document_table, $item_property_table WHERE id=ref AND tool = '".TOOL_DOCUMENT."' AND $visibility AND to_group_id = 0 AND to_user_id IS NULL  ORDER BY path ASC";
+	$sql="SELECT * from $document_table docs , $item_property_table ip WHERE docs.id=ip.ref AND ip.tool = '".TOOL_DOCUMENT."' AND $visibility AND ip.to_group_id = 0 AND ip.to_user_id IS NULL  ORDER BY docs.path ASC";
 	$result=Database::query($sql,__FILE__,__LINE__);
 	while ($row=Database::fetch_array($result))
 	{
diff --git a/main/newscorm/resourcelinker.php b/main/newscorm/resourcelinker.php
index 024552748d..87e6275f92 100755
--- a/main/newscorm/resourcelinker.php
+++ b/main/newscorm/resourcelinker.php
@@ -942,7 +942,7 @@ if ($content == "Link")
 	}
 
 	// showing the links that are in the root (having no category)
-	$sql = "SELECT * FROM ".$link_table.", ".$item_property_table." WHERE (category_id=0 or category_id IS NULL) AND tool = '".TOOL_LINK."' AND id=ref AND visibility='1'";
+	$sql = "SELECT * FROM ".$link_table." l, ".$item_property_table." ip WHERE (l.category_id=0 or l.category_id IS NULL) AND ip.tool = '".TOOL_LINK."' AND l.id=ip.ref AND ip.visibility='1'";
 	$result = Database::query($sql, __FILE__, __LINE__);
 	if (Database::num_rows($result) > 0)
 	{
@@ -961,7 +961,7 @@ if ($content == "Link")
 	$resultcategories = Database::query($sqlcategories) or die;
 	while ($myrow = @ Database::fetch_array($resultcategories))
 	{
-		$sql_links = "SELECT * FROM ".$link_table.", ".$item_property_table." WHERE category_id='".$myrow["id"]."' AND tool = '".TOOL_LINK."' AND id=ref AND visibility='1' ORDER BY display_order DESC";
+		$sql_links = "SELECT * FROM ".$link_table." l, ".$item_property_table." ip WHERE l.category_id='".$myrow["id"]."' AND ip.tool = '".TOOL_LINK."' AND l.id=ip.ref AND ip.visibility='1' ORDER BY l.display_order DESC";
 		echo "<table width=\"100%\"><tr><td bgcolor=\"#E6E6E6\"><i>".$myrow["category_title"]."</i></td></tr></table>";
 		$result_links = Database::query($sql_links, __FILE__, __LINE__);
 		while ($myrow = Database::fetch_array($result_links))
diff --git a/main/resourcelinker/resourcelinker.inc.php b/main/resourcelinker/resourcelinker.inc.php
index c61fea9b7f..470a7df131 100755
--- a/main/resourcelinker/resourcelinker.inc.php
+++ b/main/resourcelinker/resourcelinker.inc.php
@@ -99,16 +99,16 @@ function show_documents($folder)
 	// other tools do not have this feature. This only counts
 	if (is_allowed_to_edit())
 	{
-		$visibility="visibility<>'2'";
+		$visibility="ip.visibility<>'2'";
 	}
 	else
 	{
-		$visibility="visibility='1'";
+		$visibility="ip.visibility='1'";
 	}
 
 	$item_property_table = Database::get_course_table(TABLE_ITEM_PROPERTY);
 	$document_table = Database::get_course_table(TABLE_DOCUMENT);
-	$sql="SELECT * from $document_table, $item_property_table WHERE id=ref AND tool = '".TOOL_DOCUMENT."' AND $visibility AND to_group_id = 0 AND to_user_id IS NULL  ORDER BY path ASC";
+	$sql="SELECT * from $document_table docs, $item_property_table ip WHERE docs.id=ip.ref AND ip.tool = '".TOOL_DOCUMENT."' AND $visibility AND ip.to_group_id = 0 AND ip.to_user_id IS NULL  ORDER BY docs.path ASC";
 	$result=Database::query($sql,__FILE__,__LINE__);
 	while ($row=Database::fetch_array($result))
 	{
diff --git a/main/resourcelinker/resourcelinker.php b/main/resourcelinker/resourcelinker.php
index bc5680d4a3..ee0075984e 100755
--- a/main/resourcelinker/resourcelinker.php
+++ b/main/resourcelinker/resourcelinker.php
@@ -844,7 +844,7 @@ if ($content == "Link")
 	}
 
 	// showing the links that are in the root (having no category)
-	$sql = "SELECT * FROM ".$link_table.", ".$item_property_table." WHERE (category_id=0 or category_id IS NULL) AND tool = '".TOOL_LINK."' AND id=ref AND visibility='1'";
+	$sql = "SELECT * FROM ".$link_table." l, ".$item_property_table." ip WHERE (l.category_id=0 or l.category_id IS NULL) AND ip.tool = '".TOOL_LINK."' AND l.id=ip.ref AND ip.visibility='1'";
 	$result = Database::query($sql, __FILE__, __LINE__);
 	if (Database::num_rows($result) > 0)
 	{
@@ -863,7 +863,7 @@ if ($content == "Link")
 	$resultcategories = Database::query($sqlcategories) or die;
 	while ($myrow = @ Database::fetch_array($resultcategories))
 	{
-		$sql_links = "SELECT * FROM ".$link_table.", ".$item_property_table." WHERE category_id='".$myrow["id"]."' AND tool = '".TOOL_LINK."' AND id=ref AND visibility='1' ORDER BY display_order DESC";
+		$sql_links = "SELECT * FROM ".$link_table." l, ".$item_property_table." ip WHERE l.category_id='".$myrow["id"]."' AND ip.tool = '".TOOL_LINK."' AND l.id=ip.ref AND ip.visibility='1' ORDER BY l.display_order DESC";
 		echo "<table width=\"100%\"><tr><td bgcolor=\"#E6E6E6\"><i>".$myrow["category_title"]."</i></td></tr></table>";
 		$result_links = Database::query($sql_links, __FILE__, __LINE__);
 		while ($myrow = Database::fetch_array($result_links))