From Zapirain et al. (2013)"Preposition Project (Litkowski and Hargraves 2005; Litkowski and Hargraves 2006) is an effort that produced a detailed sense inventory for English prepositions, which was later used in a preposition sense disambiguation task at SemEval-2007 (Litkowski and Hargraves 2007)."
- Zapirain, Benat, et al. "Selectional preferences for semantic role classification." Computational Linguistics 39.3 (2013): 631-663.
- Litkowski, K. C. and O. Hargraves. 2005. The preposition project. In Proceedings of the ACL-SIGSEM Workshop on the Linguistic Dimensions of Prepositions and their Use in Computational Linguistic Formalisms and Applications, pages 171–179, Colchester.
- Litkowski, Ken and Orin Hargraves. 2006. Coverage and inheritance in the preposition project. In Prepositions '06: Proceedings of the Third ACL-SIGSEM Workshop on Prepositions, pages 37–44, Trento
- Litkowski, K. C. and O. Hargraves. 2007. SemEval-2007 Task 06: Word-sense disambiguation of prepositions. In Proceedings of the 4th International Workshop on Semantic Evaluations (SemEval-2007), pages 24–29, Prague.