Perhaps you should try some spelling variations:
"historical materialism" » "historica materialism" (Expand Search), "historia materialism" (Expand Search), "historicos materialism" (Expand Search)
"historicas materialism" » "historica materialism" (Expand Search), "historicos materialism" (Expand Search), "historia materialism" (Expand Search)
"historico materiales" » "historia materiales" (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: "((((\"historical materialism\") OR (\"historicas materialism\"))) OR (\"historico materiales\"))~".
• Removing quotes may allow a broader search: (((( historical materialism ) OR ( historicas materialism ))) OR ( historico materiales ))~.
• Adding a wildcard symbol may retrieve word variants: (((("historical materialism") OR ("historicas materialism"))) OR ("historico materiales"))*.