Duetting, S.

Duetting, S. & Seufert, C., 1978. Solar water pumps : technical potentialities, international R&D activities, Eschborn, Germany: German Appropriate Technology Exchange (GATE) /Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ). Available at: https://es.ircwash.org/sites/default/files/232.4-78SO-5942.pdf.