Prevalence Investigation of Novel Swine-origin Influenza A (H1N1) Virus in Some Pig Farms in Shandong Province from 2010 to 2011
ZHANG Hong-na, CHAI Tong-jie, LI Xin, WANG Hao, SUN Ling-yu, LI Xin-xian 
China Animal Husbandry & Veterinary Medicine . 2013, (3): 189 -191 .