1. Chung HY. Sexual behavior and psychology of love. In : Chung HY, editor. Medical behavioral science. Seoul: Korean Neuropsychiatric Association;2004. p. 177–183.
2. Park K, Lee HS, Kim SK, Ko JA, Yoo CJ, Kim HK, et al. Sex related social problem. In : Park K, Lee HS, Kim SK, Ko JA, Yoo CJ, Kim HK, editors. Psychology of sexuality. Seoul: Sigmapress;2008. p. 210–246.
3. Spalatin C, Allen J, Allen JS. Talk about sex. 1st ed. Seoul: Bookie;2003.
4. Mathieu T. The crocodiles. 5th ed. Seoul: Greenknowledge;2017.