1. Analysis of drugs used in out-patient practice of veterinary medicine;Agelova;Ceska Slova Farm.,2005
2. WHO Expert Committees 18th Expert Committee on the Selection and Use of Essential Medicines. Extemporaneous Reviewhttp://www.who.int/selection_medicines/committees/expert/18/policy/policy5/en/
3. European Directive 65/65/CEhttp://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31965L0065:EN:HTML