Avoid new lines between elements inside a EditorWindow

Hi, I want to know how can I avoid buttons be placed on new lines:

 public class ItemCreator : EditorWindow
 {
 
     [MenuItem("Window/Creador de Items")]
     void OnGUI() {
         GUILayout.Button("+", GUILayout.Width(40), GUILayout.Height(40));
         GUILayout.Button("+", GUILayout.Width(40), GUILayout.Height(40));
         GUILayout.Button("+", GUILayout.Width(40), GUILayout.Height(40));
         //....
     }

 }

How can I display them on the same line?

Thanks in advance.

Bye. :)