1. Content of Heavy Metals in Animal Feeds and Manures from Farms of Different Scales in Northeast China
2. Hygienical Standard for Feeds [HSF (GB 13078–2001)]http://www.chinafeed.org.cn/mem/jiangsu/center/center3-1.htm.
3. European Union. Council Directive 1999/29/Ecof 22 April1999 on the Undesirable Substances and Products in Animal Nutrition. http://ec.europa.eu/food/fs/afs/substances/substances01_en.pdf.
4. Health Canada. Pfizer and Dominion Veterinary Laboratories Suspending Sales of Veterinary Drugs Containing Roxarsone (Information Note on June 22, 2011) .http://www.hc-sc.gc.ca/dhp-mps/vet/issues-enjeux/roxarsone-eng.php.
5. U.S. Food and Drug Administration, FDA:Pfizer Will VoluntarilySuspend Sale of Animal Drug 3-Nitro (FDA Press Release June 8, (2011) .http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm258342.htm.