1. Ashliman, D. L. (2013). Sleeping Beauty. Retrieved from http://www.pitt.edu/~dash/type0410.html
2. Baldwin, B. (1996). Cogniac: A high precision pronoun resolution engine. Jill. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.45.1447
3. Representation of Concepts in Text. A Comparison of Within-document Frequency, Anaphora, and Synonymy.;S.Bonzi;Canadian Journal of Information Science,1991