Perhaps you should try some spelling variations:
"proletarian revolution" » "proletaria revolution", "proletariat revolution", "proletariado revolution", "proletarian evolucion"
"proletarian revoluciones" » "proletaria revoluciones", "proletariat revoluciones", "proletariado revoluciones"
"proletarias revolucion" » "proletaria revolucion", "proletarios revolucion", "proletariat revolucion"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("proletarian revolution") OR ((("proletarian revoluciones") OR ("proletarias revolucion"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"proletarian revolution\") OR (((\"proletarian revoluciones\") OR (\"proletarias revolucion\"))))".
• Removing quotes may allow a broader search: (( proletarian revolution ) OR ((( proletarian revoluciones ) OR ( proletarias revolucion )))).
• Adding a wildcard symbol may retrieve word variants: (("proletarian revolution") OR ((("proletarian revoluciones") OR ("proletarias revolucion"))))*.