Perhaps you should try some spelling variations:
historia americana » historia mexicana, history americas, history america
history american » history americas, history america, history's american
"lectures field " » "lectures held ", "lectures diel ", "measures field "

Try widening your search to All Fields.

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: "\"lectures field \"((historia americana) OR (history american))\"\"".
• Removing quotes may allow a broader search: lectures field ((historia americana) OR (history american)).