Perhaps you should try some spelling variations:
"basicas matematica tomo problema." » "basicas matematicas tomo problema.", "fisica matematica tomo problema.", "comicas matematicas tomo problema.", "basicas matematica como problema.", "basicas matematicas como problema.", "basicas matematica como problemas.", "basicas matematica togo problemas."
"fisica mathematics computer programs." » "fisica matematica computer programs.", "fisico matematica computer programs.", "fisico matematicas computer programs.", "fisica mathematics computer programas.", "fisica mathematics computer programa."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("basicas matematica tomo problema.") or ("fisica mathematics computer programs."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("basicas matematica tomo problema.") OR ("fisica mathematics computer programs.")).
• Removing quotes may allow a broader search: (( basicas matematica tomo problema. ) or ( fisica mathematics computer programs. )).
• Adding a wildcard symbol may retrieve word variants: (("basicas matematica tomo problema.") or ("fisica mathematics computer programs."))*.