1. The protozoan fauna of sewage disposal plants;Barker;Naturalist, Hull,1943
2. A study of the protozoa in a diffused-air activated-sludge plant;Brown,1965
3. Waste treatment protozoa;Calaway,1962
4. The fauna and flora of sewage processes. 2. Species list;Clay,1964
5. An Illustrated Key to the British Freshwater Ciliated Protozoa Commonly Found in Activated Sludge;Curds,1969