1. Reversion to virulence of attenuated canine distemper virus in vivo and in vitro;Appel;J. Gen. Virol.,1978
2. Does canine coronavirus augment the effects of subsequent parvovirus infection?;Appel;Vet. Med.,1988
3. Canine distemper virus;Appel;Virol. Monogr.,1972
4. Breed response to distemper vaccination;Baker;Proc. Anim. Care Panel,1962