3Langelotzc, Junghans T, Gunther N, et al. Problembased learning for surgery: Increased motivation with less teaching personnel [J]. Chirurg, 2005, 76(5): 481- 486.
4Kassen PC., Karshmer JE, Lile JL. Research-based practice applying the stand in nursing education [J]. Nuts Educ ,2002, 3:2.
