Perhaps you should try some spelling variations:
"la integral formulation" » "la lineal formulacion", "e integral formulation", "_ integral formulation", "et integral formulation"
"de integral formulation" » "de lineal formulacion", "e integral formulation", "de integrales formulation", "de integraca formulation"
"de integrar formulation" » "de integraca formulation", "e integral formulation", "se integra formulation"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("la integral formulation") OR ((("de integral formulation") OR ("de integrar formulation"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"la integral formulation\") OR (((\"de integral formulation\") OR (\"de integrar formulation\"))))*".
• Removing quotes may allow a broader search: (( la integral formulation ) OR ((( de integral formulation ) OR ( de integrar formulation ))))*.