Perhaps you should try some spelling variations:
"history 20th materiales del derecho" » "history 10 materiales del derecho", "history 2 materiales del derecho", "history 2.0 materiales del derecho", "history 20th materiales de derecho", "history 20th material de derecho", "history 20th materiales y derecho", "history 20th materiales dde derecho"
"historia y materiales el derecho" » "historia y materiales en derecho", "historia y materiales sol derecho", "historia y materiales web derecho", "historia de materiales el derecho", "historia y materiales de derecho"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("historia y materiales el derecho") OR ("history 20th materiales del derecho"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"historia y materiales el derecho\") OR (\"history 20th materiales del derecho\"))".
• Removing quotes may allow a broader search: (( historia y materiales el derecho ) OR ( history 20th materiales del derecho )).
• Adding a wildcard symbol may retrieve word variants: (("historia y materiales el derecho") OR ("history 20th materiales del derecho"))*.