M. Snel,
«School sanitation and hygiene education». Water, Engineering and Development Centre, Loughborough University of Technology, WEDC, Loughborough, UK, p. 5 p. : 3 fig., 2 tab., 2003.
M. Snel,
«School sanitation and hygiene education». IRC, Delft, The Netherlands, p. 63 p. : 14 tab., 2003.
K. Shordt, Snel, M., y de Graaf, S.,
«School sanitation and hygiene education indicators», in
Towards the millennium development goals - actions for water and environmental sanitation : proceedings of the 29th WEDC conference, Abuja, Nigeria, 2003, Loughborough, UK, 2003, pp. P. 63-65 : 1 tab.