Perhaps you should try some spelling variations:
"partial differential equation" » "partial differential equations", "partial difference equations"
"partial difference equationss" » "partial difference equations", "partial difference equation", "partial differenced equations", "potential difference equationss", "racial differences equationss"
"partial differences equations" » "partial difference equations", "partial difference equation", "partial differential equations", "spatial differences equations", "particles differences equations", "arterial differences equations", "potential differences equations", "racial differencess equations"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("partial differential equation") OR ((("partial difference equationss") OR ("partial differences equations")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"partial differential equation\") or (((\"partial difference equationss\") OR (\"partial differences equations\"))))".
• Removing quotes may allow a broader search: (( partial differential equation ) or ((( partial difference equationss ) OR ( partial differences equations )))).
• Adding a wildcard symbol may retrieve word variants: (("partial differential equation") or ((("partial difference equationss") OR ("partial differences equations"))))*.