4David TJ, Dolmans DH, Patel L, et al. Problem-based learning as an alternative to lecture-based continuing medical education. J R Soc Med,1998,91(12) :626-630.
5Kolh S, Wengenroth L, Hege I, et al. Case based e-learning in occupational medicine-a European approach. J Occup Environ Med, 2009,51 (6) : 647-653.
6Schmidt HG, Rotgans JI, Yew EH. The process of problem- based learning: what works and why. Med Edue,2011,45(8) : 792-806.
9Jemal A, Bray F, Center MM, et al. Global cancer staristics[J]. CA Cancer J Clin, 2011, 61(2):69-90.
10Macfarlane G], Boyle P, Evstifeeva TV, et al. Rising trends of oral cancer mortality amongmales worldwide: The return of an old public health problem[J], Cancer Causes Control, 1994,5:259-265.