L. K. National W. Ratmalana,
Guidelines for latrine selection and construction, vol. no. D6. Ratmalana, Sri Lanka: National Water Supply and Drainage Board, 1988, p. iv, 61 p.: fig., tab.
S. Cairncross,
Small scale sanitation, 3rd ed.ª ed., vol. no. 8. London, UK: Ross Institute of Tropical Hygiene, 1988, p. x, 60 p. : fig., tab., pl.