1. Pet Industry Market Size, Trends & Ownership Statisticshttps://www.americanpetproducts.org/press_industrytrends.asp
2. Pet Food: Including Impact of Covid-19www.mintel.com
3. 2018 Official Publication,2018
4. Introduction to commercial pet foods;Crane,2000
5. Preferences of dogs for various meats;Lohse;J. Am. Anim. Hosp. Assoc.,1974