Perhaps you should try some spelling variations:
"poly equation" » "golay equation", "pol's equation", "pol equations", "pooly equation", "polly equation"
"pole equation" » "cole equation", "people equation", "pol's equation", "poole equation", "polle equation"
"py equation" » "key equation", "ray equation", "prey equations"
"pol equation" » "pool equation", "poll equation"

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: (((("pol equation") OR ("pole equation"))) OR ((("poly equation") OR ("py equation")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"pol equation\") or (\"pole equation\"))) or (((\"poly equation\") OR (\"py equation\"))))".
• Removing quotes may allow a broader search: (((( pol equation ) or ( pole equation ))) or ((( poly equation ) OR ( py equation )))).
• Adding a wildcard symbol may retrieve word variants: (((("pol equation") or ("pole equation"))) or ((("poly equation") OR ("py equation"))))*.