Andreescu, T., & Andreescu, T. F. (2004). 103 trignometry problems. Birkhauser.
Chicago Style aipamenaAndreescu, Titu, and Titu; Feng Andreescu. 103 Trignometry Problems. Boston: Birkhauser, 2004.
MLA aipamenaAndreescu, Titu, and Titu; Feng Andreescu. 103 Trignometry Problems. Birkhauser, 2004.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.