8G Dickerson, J Grimes. Effectiveness of selection for efficien- cy of gain in Duroc swine [J]. Journal of Animal Science, 1947, 6(3): 265-287.
9R L Payne, R T Zijlstra. A guide to application of net energy in swine feed formulation[Z]. in Proc. 2007 Banff Pork Sem- inar. Advances in Pork Production, 2007: 159-165.