<ref name="Ren_2002">{{cite book |first1=Z.-Y. |last1=Ren |year=2002 |title=Animal Science. In celebration of Professor Zhemin's 70th birthday and 50 years of teaching. [In Chinese.] |url= |location=Xi'an |publisher=Shanxi Normal University Press |pages=433 pp. |isbn=}}</ref>