Perhaps you should try some spelling variations:
camilo perez » castillo perez, calvo perez, pablo perez
castro perez » castillo perez, arturo perez, castro pedro
medicion de » medicina de
campo perez » campos perez, crespo perez, amparo perez
edicion e » edicion de, edicion en, medicion e
de campo » de cambio, el campo

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( medicion de campo perez la pau ; ) or ( edicion e ((camilo perez) OR (castro perez)) la paz ; ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( medicion de campo perez la pau ; ) OR ( edicion e ((camilo perez) OR (castro perez)) la paz ; )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( medicion de campo perez la pau ; ) or ( edicion e ((camilo perez) OR (castro perez)) la paz ; ))".
• Adding a wildcard symbol may retrieve word variants: (( medicion de campo perez la pau ; ) or ( edicion e ((camilo perez) OR (castro perez)) la paz ; ))*.