Perhaps you should try some spelling variations:
"michael warren schwarz" » "michael waren schwarz" (Expand Search), "michael warten schwarz" (Expand Search), "michael wahren schwarz" (Expand Search), "michael warren schwarzes" (Expand Search)
"michael karren schwarz" » "michael karren schwarzes" (Expand Search), "michael karten schwarz" (Expand Search)
"michael karren schwarzen" » "michael karren schwarzesen" (Expand Search), "michael karten schwarzen" (Expand Search), "michael karren schwaben" (Expand Search)

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: "((\"michael warren schwarz\") OR (((\"michael karren schwarz\") OR (\"michael karren schwarzen\"))))~".
• Removing quotes may allow a broader search: (( michael warren schwarz ) OR ((( michael karren schwarz ) OR ( michael karren schwarzen ))))~.
• Adding a wildcard symbol may retrieve word variants: (("michael warren schwarz") OR ((("michael karren schwarz") OR ("michael karren schwarzen"))))*.