“Indicator fact sheet signals 2001. Chapter households”. European Environment Agency (EEA), Copenhagen, Denmark.
N. L. C. I. R. A. N. - The Hague,
“Indigenous knowledge and development monitor”. Centre for International Research and Advisory Networks, NUFFIC, The Hague, The Netherlands.
C. Hunt and Biran, A.,
“Indoor air pollution”. Water, Engineering and Development Centre, Loughborough University of Technology, WEDC, Loughborough, UK, p. 3 pag.
“InfoGate”. German Appropriate Technology Exchange (GATE) /Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), Eschborn, Germany.
“Informal paper / WSP-ESA”. Water and Sanitation Program - East and Southern Africa, Nairobi, Kenya.