Tsutsui, T., Stabenfeldt, GH. 1993. "Biology of ovarian cycles, pregnancy and pseudopregnancy in the domestic cat". In J Reprod Fertil Suppl. Available at: https://pubmed.ncbi.nlm.nih.gov/8229938
Casal, ML., Jezyk, PF., Giger, U. 1996. "Transfer of colostral antibodies from queens to their kittens". In Am J Vet Res. Available at: https://pubmed.ncbi.nlm.nih.gov/8915447