1. Anon 1968 European Convention for the Protection of Animals During International Transport European Treaty Series No. 65
2. Brummer , H. 1978 Verhaltensstörungen Nutztierethologie H. H. Sambraus P. Parey 281 292
3. Contribution of ethology to clinical interpretation of the horse's welfare;Ewbank;Equine vet. J.,1985
4. Ethical problems for veterinary surgeons at equestrian events;Gerber;Equine vet. J.,1984