World Health Organization. (1994). Operation and Maintenance of Urban Water Supply and Sanitation Systems: A guide for managers. World Health Organization.
Citação do estilo Chicago (17ª ed.)World Health Organization. Operation and Maintenance of Urban Water Supply and Sanitation Systems: A Guide for Managers. Switzerland: World Health Organization, 1994.
Citação MLA (9ª ed.)World Health Organization. Operation and Maintenance of Urban Water Supply and Sanitation Systems: A Guide for Managers. World Health Organization, 1994.
Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.