Perhaps you should try some spelling variations:
coleccion practicas » coleccion practica, coleccion didactica, coleccion actas
economica mexicana » economico mexicano, economica mexico, tecnologica mexicana
economia mexicana » economica mexico, economia espana, academia mexicana
la cirugia » en cirugia, de cirugia
de y » de _, de a, de 3

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: coleccion practicas de y ((economica mexicana) OR (economia mexicana)) la cirugia.~.
• Adding a wildcard symbol may retrieve word variants: coleccion practicas de y ((economica mexicana) or (economia mexicana)) la cirugia.*.