Perhaps you should try some spelling variations:
instrumento didacticos » instrumentos didacticos, instrumentacion didactica
instrumento didactico » instrumentos didacticos, instrumentacion didactica, instrumento pedagogico
publicacion de » publicaciones de, aplicacion de
minera de » mineria de, mineral de, minerales de
y minera » y mineral, y mineria, y minero

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

• Performing a fuzzy search may retrieve terms with similar spellings: publicacion de ((instrumento didacticos) or (instrumento didactico)) y minera de espana ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: publicacion de ((instrumento didacticos) OR (instrumento didactico)) y minera de espana ;.
• Adding a wildcard symbol may retrieve word variants: publicacion de ((instrumento didacticos) or (instrumento didactico)) y minera de espana ;*.