International Commission on Irrigation and Drainage & Congress on Irrigation and Drainage. (1967). Sixth congress on irrigation and drainage, post-congress written discussions. Questions 19, 20, 21 & 22: Sixieme congres de irrigations et du drainage, discussions ecrites post-congres.
Chicago-viite (17. p.)International Commission on Irrigation and Drainage ja Congress on Irrigation and Drainage. Sixth Congress on Irrigation and Drainage, Post-congress Written Discussions. Questions 19, 20, 21 & 22: Sixieme Congres De Irrigations Et Du Drainage, Discussions Ecrites Post-congres. New Delhi, 1967.
MLA-viite (8. p.)International Commission on Irrigation and Drainage ja Congress on Irrigation and Drainage. Sixth Congress on Irrigation and Drainage, Post-congress Written Discussions. Questions 19, 20, 21 & 22: Sixieme Congres De Irrigations Et Du Drainage, Discussions Ecrites Post-congres. 1967.