Graham, JP; Polizzotto, ML (May 2013). "Pit latrines and their impacts on groundwater quality: a systematic review". Environmental health perspectives. 121 (5): 521–30. PMID23518813. डीओआइ:10.1289/ehp.1206028.
Graham, JP; Polizzotto, ML (May 2013). "Pit latrines and their impacts on groundwater quality: a systematic review". Environmental health perspectives. 121 (5): 521–30. PMID23518813. डीओआइ:10.1289/ehp.1206028.