Παραπομπή APA

Croft, H. T., Falconer, K. J., & Guy, R. K. (1991). Unsolved problems in geometry. Springer-Verlag.

Παραπομπή Chicago Style

Croft, Hallard T., K. J. Falconer, και Richard K. Guy. Unsolved Problems in Geometry. New York: Springer-Verlag, 1991.

Παραπομπή MLA

Croft, Hallard T., et al. Unsolved Problems in Geometry. Springer-Verlag, 1991.