Y. M. Sternberg and Knight, R.,
“Final report on the development and testing of the robovalve”, vol. AID contract AID/ta-c-1461. International Rural Water Resources Development Laboratory, College Park, Maryland, p. 70 p. : 8 fig., 4 tab., 5 app., 1978.
J. Cuthbert,
“Guidelines for comparative testing of products : hand/foot pumps, part I and II”, vol. Z.9977. Consumers' Association Harpenden Rise Laboratory, London, UK, p. Various paging : fig., 1978.