Perhaps you should try some spelling variations:
"The comparison series" » "The comparison studies", "The comparison string", "The comparison sites"
"The compass series" » "The compact series", "The compass varies", "The compass exercises"
"the complex series" » "the complex services", "the complex queries", "the complete series"

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