Perhaps you should try some spelling variations:
"racial differences equation" » "racial differences equations", "racial differenced equations", "racial differences education", "regional differences equation", "social differences equation", "rational differences equation", "crucial differencess equation"
"racial difference equation" » "racial difference equations", "racial differential equation", "racial differential equations", "social difference equation", "rational difference equation", "crucial differences equation"
"facial difference equation" » "facial difference equations", "facial differential equation", "facial differential equations", "social difference equation", "partial difference equation", "social differences 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: (((("racial difference equation") OR ("facial difference equation"))) OR ("racial differences equation")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"racial difference equation\") OR (\"facial difference equation\"))) or (\"racial differences equation\"))".
• Removing quotes may allow a broader search: (((( racial difference equation ) OR ( facial difference equation ))) or ( racial differences equation )).
• Adding a wildcard symbol may retrieve word variants: (((("racial difference equation") OR ("facial difference equation"))) or ("racial differences equation"))*.