Perhaps you should try some spelling variations:
"risk gustav heinrich" » "risk auguste heinrich", "krieg gustav heinrich"
"werk gustav resch" » "werk gustav roth", "werner gustav resch", "heart gustav resch"
"risk gustav erich" » "risk gustavi erici", "risk gustav friedrich", "risk gustav brink", "krieg gustav erich"

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: "((\"werk gustav resch\") OR (((\"risk gustav erich\") OR (\"risk gustav heinrich\"))))".
• Removing quotes may allow a broader search: (( werk gustav resch ) OR ((( risk gustav erich ) OR ( risk gustav heinrich )))).
• Adding a wildcard symbol may retrieve word variants: (("werk gustav resch") OR ((("risk gustav erich") OR ("risk gustav heinrich"))))*.