Perhaps you should try some spelling variations:
"nonpositivism" » "noncognitivism", "nonpositive", "nonpositively", "nonpositives", "nonpositivity"
"antipositivism" » "antipositives", "antipositivity"
"positivism" » "positives", "positivity"
"neopositivism" » "neopositives", "neopositivity"

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