Perhaps you should try some spelling variations:
"competencias matematicas computer programming." » "competencia matematica computer programming.", "competencias basicas computer programming.", "competencias genericas computer programming.", "competencias mathematics computer programming.", "competencias matematicas comics programming.", "competencias matematicas computer programs.", "competencias matematicas computer program."
"basicas matematicas como programar." » "comicas matematicas como programar.", "benditas matematicas como programar.", "fisica matematica como programar.", "basicas matematica como programar.", "basicas matematicas con programar.", "basicas matematica tomo programar.", "basicas matematicas como programa.", "basicas matematicas campo programa.", "basicas matematicas con programa."

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: (("basicas matematicas como programar.") or ("competencias matematicas computer programming."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("basicas matematicas como programar.") OR ("competencias matematicas computer programming.")).
• Removing quotes may allow a broader search: (( basicas matematicas como programar. ) or ( competencias matematicas computer programming. )).
• Adding a wildcard symbol may retrieve word variants: (("basicas matematicas como programar.") or ("competencias matematicas computer programming."))*.