Perhaps you should try some spelling variations:
"vassal" » "vassall", "vassil", "vassar"
"vassals" » "vassalls", "vassils", "vassars", "vassilis"
"vassars" » "vassar", "nassars", "vassart"
"nassauer" » "passauer", "assauer", "hassauer"

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: ("vassal" OR (("vassals" OR "vassars") OR "nassauer")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(\"vassal\" or ((\"vassals\" OR \"vassars\") or \"nassauer\"))".
• Removing quotes may allow a broader search: ( vassal or (( vassals OR vassars ) or nassauer )).
• Adding a wildcard symbol may retrieve word variants: ("vassal" or (("vassals" OR "vassars") or "nassauer"))*.