Cita APA (7a ed.)

Mathematical Association of America, ebrary, Inc, Wells, D., & Faires, J. D. (2008). The contest problem book IX: American Mathematics Competitions (AMC 12) 2001-2007. Mathematical Association of America.

Cita Chicago Style (17a ed.)

Mathematical Association of America, Inc ebrary, Dave Wells, y J. Douglas Faires. The Contest Problem Book IX: American Mathematics Competitions (AMC 12) 2001-2007. Washington, D.C.: Mathematical Association of America, 2008.

Cita MLA (9a ed.)

Mathematical Association of America, et al. The Contest Problem Book IX: American Mathematics Competitions (AMC 12) 2001-2007. Mathematical Association of America, 2008.