Subject	textbook
Predicate	has_property
Object	secondary source
Modality	Modality Occurrences
Polarity	POSITIVE
Plausibility	0.3527
Neighborhood Sigma	0.3527
Local Sigma	0.5744
Example Sentences	Sentence Occurrences Source textbooks are secondary sources 2 Google Autocomplete a textbook is a secondary source 20 Google Autocomplete