Techniques for the collection and reporting of data on community water supply: Report of a WHO Scientific group
World Health Organisation
Techniques for the collection and reporting of data on community water supply: Report of a WHO Scientific group - Geneva WHO 1972 - 24 - WHO technical report series; No.490 .
Techniques for the collection and reporting of data on community water supply: Report of a WHO Scientific group - Geneva WHO 1972 - 24 - WHO technical report series; No.490 .