Perhaps you should try some spelling variations:
history mexican » history american, history mexico, history lexicon
history medical » history medieval, history media, history medicine
lecture des » lecture de, lecture dans, lecture day
lectures de » lectures _, lectures 1, lectures a
lectures 2 » lectures _, lectures 1

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((lecture des) OR (((lectures de) OR (lectures 2)))) ((history mexican) OR (history medical)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((lecture des) or (((lectures de) OR (lectures 2)))) ((history mexican) or (history medical))".
• Adding a wildcard symbol may retrieve word variants: ((lecture des) or (((lectures de) OR (lectures 2)))) ((history mexican) or (history medical))*.