Perhaps you should try some spelling variations:
"economicos matematicos computer program." » "economics mathematical computer program.", "economia matematica computer program.", "comicas matematicas computer program.", "economicos mathematics computer program.", "economicos animation computer program.", "economicos matematicos computer programs."
"basicas matematicas como programming." » "comicas matematicas como programming.", "benditas matematicas como programming.", "fisica matematica como programming.", "basicas matematica como programming.", "basicas matematicas con programming.", "basicas matematica tomo programming.", "basicas matematicas control programming.", "basicas matematicas logic programming.", "basicas matematicas computer programming."

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("economicos matematicos computer program.") or ("basicas matematicas como programming."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("economicos matematicos computer program.") OR ("basicas matematicas como programming.")).
• Removing quotes may allow a broader search: (( economicos matematicos computer program. ) or ( basicas matematicas como programming. )).
• Adding a wildcard symbol may retrieve word variants: (("economicos matematicos computer program.") or ("basicas matematicas como programming."))*.