Perhaps you should try some spelling variations:
"methode van bavel / gtt" » "methode von bavel / gtt", "methode vi bavel / gtt", "methode vii bavel / gtt", "methode vian bavel / gtt", "methode 3an bavel / gtt", "methode 4an bavel / gtt"
"methode v bavula / gtt" » "methode vi bavula / gtt", "methode 3 bavula / gtt", "methode 4 bavula / gtt", "methode v.v bavula / gtt"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("methode van bavel / gtt") OR ((("methode v bavula / gtt") OR ("methode 2 bavula / gtt")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"methode van bavel / gtt\") or (((\"methode v bavula / gtt\") OR (\"methode 2 bavula / gtt\"))))".
• Removing quotes may allow a broader search: (( methode van bavel / gtt ) or ((( methode v bavula / gtt ) OR ( methode 2 bavula / gtt )))).
• Adding a wildcard symbol may retrieve word variants: (("methode van bavel / gtt") or ((("methode v bavula / gtt") OR ("methode 2 bavula / gtt"))))*.