Perhaps you should try some spelling variations:
"von birkhauser classes" » "von brauer classes", "von parkhausern classes", "v burkhauser classes", "von kindhauser classes"
"von birkhauser plates" » "von birkhauser peter", "von birkhauser completed", "von parkhausern plates", "v burkhauser plates", "von kindhauser plates"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"von birkhauser classes\") OR (\"von birkhauser plates\"))".
• Removing quotes may allow a broader search: (( von birkhauser classes ) OR ( von birkhauser plates )).
• Adding a wildcard symbol may retrieve word variants: (("von birkhauser classes") OR ("von birkhauser plates"))*.