Perhaps you should try some spelling variations:
coleccion practica » coleccion didactica
academico mexico » academicos mexico, academico excmo, academico leido
la cirugia » en cirugia, de cirugia
ethel del » ethel el
edel del » fidel del, el del, piel del
del dem » del de, del des, el dem

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 practica ((((edel del) OR (ethel del))) OR (del dem)) academico mexico la cirugia.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "coleccion practica ((((edel del) OR (ethel del))) or (del dem)) academico mexico la cirugia.~".
• Adding a wildcard symbol may retrieve word variants: coleccion practica ((((edel del) OR (ethel del))) or (del dem)) academico mexico la cirugia.*.