Perhaps you should try some spelling variations:
"mars colonization history" » "mars communication history", "mars organization history", "mars cooperation history", "mrsa colonization history", "its colonization history", "jews colonization history"
"coca colonization songs" » "coca colonization still", "coca colonization work", "coca decolonization notes", "mrsa colonization songs", "africa colonization songs", "_ colonization songs"
"human colonization songs" » "human colonization still", "human colonization work", "human decolonization notes", "human communication songs", "human civilization songs", "human cognition songs"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("mars colonization history") or ((("coca colonization songs") OR ("human colonization songs"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("mars colonization history") OR ((("coca colonization songs") OR ("human colonization songs")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"mars colonization history\") or (((\"coca colonization songs\") OR (\"human colonization songs\"))))".
• Removing quotes may allow a broader search: (( mars colonization history ) or ((( coca colonization songs ) OR ( human colonization songs )))).
• Adding a wildcard symbol may retrieve word variants: (("mars colonization history") or ((("coca colonization songs") OR ("human colonization songs"))))*.