"Worms in sheep and their control: handbook no. 1" - Merck, Sharp and Dohme (Australia) Pty Ltd, 1962. Discusses the types of worms that commonly infest sheep and relates details of a new all-worm drench called Thibenzole, introduced onto the market in early 1962.sheep - parasites animal health sheep drenching, merck, sharp and dohme (australia) pty ltd, thibenzole, sheep - parasites, animal health, sheep drenching