Croft, H. T., Falconer, K. J., & Guy, R. K. (1991). Unsolved problems in geometry. Springer-Verlag.
Chicago Style aipamenaCroft, Hallard T., K. J. Falconer, and Richard K. Guy. Unsolved Problems in Geometry. New York: Springer-Verlag, 1991.
MLA aipamenaCroft, Hallard T., et al. Unsolved Problems in Geometry. Springer-Verlag, 1991.
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