Perhaps you should try some spelling variations:
based representation » based presentation, self representation, data representation
space studies » scale studies, peace studies, sage studies
race studies » tracer studies, peace studies, trade studies
code earth » code search
one earth » one heart, one part, one birth

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

• Performing a fuzzy search may retrieve terms with similar spellings: commercial ((code earth) or (one earth)) based representation ((space studies) OR (race studies)).~.
• If you are trying to use Boolean operators, they must be ALL CAPS: commercial ((code earth) OR (one earth)) based representation ((space studies) OR (race studies)).*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "commercial ((code earth) or (one earth)) based representation ((space studies) OR (race studies)).*".