A. M. Wright y Bakalian, A. E.,
«Intermediate sewerage : cost-efficient sewerage», vol. no. WS-4. World Bank, Infrastructure and Urban Development Department, Washington, DC, USA, p. 4 p.: fig., 1990.
A. M. Wright,
«Strategic sanitation planning», vol. no. WS-1. World Bank, Infrastructure and Urban Development Department, Washington, DC, USA, p. 2 p.: fig., 1990.