1. 01 មករា 1983 This booklet is a manual on masonry well construction, written for the layman with little or no technical training. 50 pages, illustrated
  2. 01 មករា 1964 Department of Economic and Social Affairs, United Nations 87 pages, illustrated, photos, plus tables of figures
  3. 01 មករា 1955 144 pages, illustrated, photos