Perhaps you should try some spelling variations:
"path lineal formulacion" » "path la formulacion", "path una formulacion", "path anexo formulacion", "paths lineal formulacion", "pat lineal formulacion"
"et integral formulation" » "e integral formulation", "_ integral formulation", "la integral formulation"
"de integral formulation" » "e integral formulation", "de integrar formulation", "de integrales formulation"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"path lineal formulacion\") OR (((\"et integral formulation\") OR (\"de integral formulation\"))))~".
• Removing quotes may allow a broader search: (( path lineal formulacion ) OR ((( et integral formulation ) OR ( de integral formulation ))))~.
• Adding a wildcard symbol may retrieve word variants: (("path lineal formulacion") OR ((("et integral formulation") OR ("de integral formulation"))))*.