go to ORKG: http://orkg.org/orkg/predicate/P31
has contribution
- http://orkg.org/orkg/shapes/orkgc_C16005
- http://orkg.org/orkg/shapes/orkgc_Paper
- http://orkg.org/orkg/shapes/orkgc_FeaturedPaper
- http://orkg.org/orkg/shapes/orkgc_Contribution
- http://orkg.org/orkg/shapes/orkgc_Resource
- http://orkg.org/orkg/shapes/orkgc_Venue
- http://orkg.org/orkg/shapes/orkgc_PaperDeleted
- http://orkg.org/orkg/shapes/orkgc_ContributionDeleted
- http://orkg.org/orkg/shapes/orkgc_SmartReview