|The donkey knocks to greet, because he is hungry or unhappy, or when he mates||"Reactivity of lichen lectins with blood typed canine erythrocytes"|
|Giger U, Kilrain CG, Filippich LJ, Bell K November 1989||It is also expressed by moans, grunts, sighs, or blows, and much by body language: loving rubbing and nibbling, menacing looks, lying ears, and lashing of the tail in signs of aggression|
"Frequencies of feline blood groups in the United States".
|at BGMUT Blood Group Antigen Gene Mutation Database at ,• Symons M, Bell K 1991||Journal of Equine Veterinary Science|
|at BGMUT Blood Group Antigen Gene Mutation Database at ,• at BGMUT Blood Group Antigen Gene Mutation Database at ,• "Determination of the prevalence of feline blood types in the UK"||Malik R, Griffin DL, White JD, Rozmanec M, Tisdall PL, Foster SF, Bell K, Nicholas FW 2005|
Andrews GA, Chavey PS, Smith JE November 1992.14
|"Expansion of the canine A blood group system"|