ebrary, Inc, Leigh, R. B., & Liu, C. A. (2011). Hungarian problem book IV. Mathematical Association of America.
芝加哥风格引文ebrary, Inc, Robert Barrington Leigh, 与 Chiang-Fung Andrew Liu. Hungarian Problem Book IV. [Washington, D.C.]: Mathematical Association of America, 2011.
MLA引文ebrary, Inc, et al. Hungarian Problem Book IV. Mathematical Association of America, 2011.
警告：这些引文格式不一定是100％准确.