X. Sun, K. Chen, E.P. Berg and J.D. Magolski
Journal of Animal and Veterinary Advances 10 ( 12 ): 1504 - 1511 , 2011
W Junfang, Z Biao, Z Weijun, S Zhang, W Yinyin and K. Chen
Journal of Public Health 31 ( 4 ): 530 - 540 , 2009