Perhaps you should try some spelling variations:
"fisica matematica computer programmers." » "fisica matematica computer programs.", "fisica matematica computer programming.", "fisica matematica computers programming.", "fisica mathematics computer programmers."
"competencias basicas computer programas." » "competencias basicas computer programs.", "competencias basicas computer program.", "competencias basicas computer programming.", "competencias basic computer programas.", "competencias pascal computer programas.", "competencias business computer programas."

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