I. L. Nyumbu, Scott, M., Seager, M., y Wang, C.,
«Agua potable y saneamiento : manual de principios y metodos financieros». World Health Organization, Community Water Supply & Sanitation Unit, Geneva, Switzerland, p. iv, 100 p.: fig., 1990.
I. L. Nyumbu, Scott, M., Seager, M., y Wang, C.,
«Approvisionnement public en eau et assainissement : principes et methodes de gestion financiere manuel». World Health Organization, Community Water Supply & Sanitation Unit, Geneva, Switzerland, p. iv, 100 p.: fig., 1990.
I. L. Nyumbu, Scott, M., Seager, M., y Wang, C.,
«Water supply and sanitation : handbook of financial principles and methods». World Health Organization, Community Water Supply & Sanitation Unit, Geneva, Switzerland, p. iv, 100 p.: fig., 1990.