S. A. Ross, Guo, P. H. M., and Jank, B. E.,
“Design and selection of small wastewater treatment systems”, vol. no. EPS 3-WP-80-3. Canada, Ministry of Supply and Services, Ottawa, Ont, Canada, p. xiii, 311 p. : 71 fig., 31 tab., 1980.
A. Breuer and Netzband, A.,
“Small scale irrigation”. German Appropriate Technology Exchange (GATE) /Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), Eschborn, Germany, p. 97 p. : fig. tab., 1980.