Perhaps you should try some spelling variations:
"computers mathematical computer programs." » "copulas mathematical computer programs.", "costs mathematical computer programs.", "computers mathematics computer programs.", "computers mathematical computer programas.", "computers mathematical computer programa."
"basicas matematicas con programmers." » "comicas matematicas con programmers.", "benditas matematicas con programmers.", "fisica matematica con programmers.", "basicas matematicas en programmers.", "basicas matematica en programmers.", "basicas matematicas y programmers."

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