3Hobbs J E. Information asymmetry and the role of traceability sys-tems[J]. Agribusiness, 2004, 20(4): 397-415.
4Tonsor G T, Schroeder T C. Livestock identification: Lessons for the US beef industry from the Australian system[J]. Journal of In- ternational Food & Agribusiness Marketing, 2006, 18(3/4): 103-118.
5Golan E, Krissoff B, Kuchler F, et al. Traceability in the US food supply: economic theory and industry studies[M].US Department of Agriculture, Economic Research Service, 2004.