Biblio

I. Hespanhol and Helmer, R., “Control de la contaminacion del agua : guia para la aplicacion de principios relacionados con la calidad del agua”. CEPIS (Centro Panamericano de Ingenieria Sanitaria y Ciencias del Ambiente), Lima, Peru, p. xvi, 546 p. : fig., tab., 1999.

R. Helmer, Ongley, E. D., and Peters, N. E., “Water quality - a global concern : paper no. 13”, in Report of the expert group meeting on strategic approaches to freshwater management : Harare, Zimbabwe, 27 - 30 January 1998, 1998, p. 26 p. : 3 fig.

I. Hespanhol and Helmer, R., Water pollution control : a guide to the use of water quality management principles. London, UK: E & FN Spon, 1997, p. xvi, 510 p. : boxes, fig., maps, tab.

R. Helmer, “Water pollution control”, in [Third Global Forum : Barbados : 30 October - 3 November 1995 : various papers presented], 1996, p. 31 p.

I. Hespanhol and Helmer, R., “Presentation des nouveaux sujets pour le Conseil de Concertation pour l'Approvisionnement en Eau et l'Assainissement : La Reunion du Conseil a Rabat, 7-10 Septembre 1993 : l'eau, les limites de la croissance ..”, presented at the 1993-01-01, Geneva, Switzerland, 1993, p. 24 p.: 7 box, 4 fig.

R. Helmer and Ballance, R. C., “Potable water quality requirements : WHO”, Water supply : the review journal of the International Water Supply Association, p. p. IR 8/18 - IR 8/25 : 9 tab., 1991.

B. J. Lloyd and Helmer, R., Surveillance of drinking water quality in rural areas. Harlow, UK: Longman Publishers, 1991, p. xvi, 171 p.: fig., tab., photogr.

D. Wheeler, Dahi, E., and Helmer, R., “WHO/DANIDA course on surveillance and control of drinking water quality, Arusha, November 1990”. Centre for Developing Countries, Technical University of Denmark, Lyngby, Denmark, p. Ca. 250 p.: fig., tab., 1990.