Akbari sari M, Asadi E, Fakharzadeh A and Sokhtanlo M, 2008. The survey of consumers' attitudes and factors affecting the acceptance of organic agricultural products. Iranian Journal of Agricultural Economics and Development 39: 133-144.
Amemyia T, 1985. Advanced Econometrics, Cambridge, Massachusetts, Harvard University Press.
Bauman D E, Mather I H, Wall RJ and Lock AL, 2006. Major advances associated with the biosynthesis of milk. Journal Dairy Science 89: 1235–1243.
Bessa R J B, Santos-Silva J, Ribeiro J M R and Portugal AV, 2000. Reticulo-rumen biohydrogenation and the enrichment of ruminant edible products with linoleic acid conjugated isomers. Livestock Production Science 63: 201–211.
Chen T, Song M, Nansekin T, Takeuchi Sh, Zhou H and Li D, 2013. Consumer willingness to pay for food safety in Shanghai China: A case study of gap–certified milk. Journal of the Faculty of Agriculture, Kyushu University 58 (2): 467–473.
Ghorbani M and Zare EF, 1999. An introduction to environmental valuation. Mashhad, Iran. Ferdowsi University Press, Mashhad.
Gunduz O, and Bayramoghlo Z, 2011. Consumer willingness to pay chicken meat in Samsun Province of Turkey. Journal of Animal and Veterinary Advances 21(3): 331-333.
Haghjoo M, Hayatiba, Mohammad Rezayi R, Pishbahar A and Dashti Gh, 2011. Factors affecting the desire to pay the potential of consumers for healthy products (Case study: employees of the agricultural organization of east Azarbaijan province). Knowledge of Agriculture and Sustainable Production 21(3). 105-117.
Heckman J, 1979. Sample selection bias as specification error, Econometric, 97: 153-161.
Maddala GS, 1983. limited dependent and qualitative variables in economics, Newyork: Cambridge University Press, Cambridge.
Maddala GS, 2002. Introduction to econometrics (3rd Edition). Chichester John Wieley.
Mosavi SN, Sajedi SH and Mozafari Z, 2016. Valuation of dairy products and organic proteins and factors affecting the desire to pay a case study of milk in Shiraz. Applied Economic Studies of Iran 17(5):273-300.
Simopoulos A P, 1999. Essential fatty acids in health and chronic disease. American Journal of Clinical Nutrition 70: 560S–569S.
Van Loo E, CaputoV, Nayga R, Pieniak Z and Verbeke W, 2013. Consumer attitudes, knowledge, and consumption of organic yogurt. American Dairy Science 96(4): 2118-2129.
Williams C M, 2000. Dietary fatty acids and human health. Ann. Zootech 49: 165–180.