Biblio

S. L. Ng and Toh, A. S., “Pilot pipeline renovation in Malaysia using 'no-dig' techniques”, Aqua : journal of water supply research and technology, pp. p. 113-119: 4 fig., 6 tab., 1994.

L. J. H. Janssen, “The local production of handpumps for drinking water in developing countries”. L.J.H. Janssen, Buren, The Netherlands, p. ii, 25 p.: fig., 1984.