6Barrows HS.A taxormmy of problem based learning methods[J]. Meal E- due, 1986,20:481-486.
7Jonathan DB, Joy Robinson, Jonathan Smout. Problem-based learning for surgical trainces[J]. Ann R CoU Stag Engl,2002,84:227-229.
8Dolmaixs DH, De Grave W, Wolflmge N IH, et al. Pmblem- learn- ing: future challenges for educational practice and research[ J ]. Med Educ, 2005,39(7) :732-741.
