B. Ministry o BT,
“Report national health survey 2000”. Bhutan, Ministry of Health and Education, Department of Health Services, Thimphu, Bhutan, p. 38 p. : charts, tabs., 2000.
T. Keating and Lawson, R.,
“Water efficiency of retrofit dual flush toilets”. Environment Agency, Bristol, UK, p. 41 p. : fig., plates, tabs., 2000.