Perhaps you should try some spelling variations:
"10 step theories" » "10 deep theories", "10 system theories", "10 nested theories"
"10 steps series" » "10 steps seem", "10 steps stages"
"10 step series" » "10 step serial", "10 step energies", "10 step secrets"
"10 steps set" » "10 steps asset", "10 steps step", "10 steps seem"

Try widening your search to All Fields.

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: (((("10 steps series") OR ((("10 step series") OR ("10 step theories"))))) OR ("10 steps set")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"10 steps series\") or (((\"10 step series\") OR (\"10 step theories\"))))) or (\"10 steps set\"))".
• Removing quotes may allow a broader search: (((( 10 steps series ) or ((( 10 step series ) OR ( 10 step theories ))))) or ( 10 steps set )).
• Adding a wildcard symbol may retrieve word variants: (((("10 steps series") or ((("10 step series") OR ("10 step theories"))))) or ("10 steps set"))*.