Cita APA (7th ed.)

Guy, R. K. (1981). Unsolved problems in number theory. Springer-Verlag.

Cita Chicago (17th ed.)

Guy, Richard K. Unsolved Problems in Number Theory. Nueva York: Springer-Verlag, 1981.

Cita MLA (9th ed.)

Guy, Richard K. Unsolved Problems in Number Theory. Springer-Verlag, 1981.