Kanok-Nukulchai, W.

Kanok-Nukulchai, W. & Robles-Austriaco, L., 1985. Ferrocement biogas digester, (IFIC Publications no. 41) Bangkok, Thailand: International Ferrocement Information Center. Available at: https://www.ircwash.org/sites/default/files/352.1-85FE-6337.pdf.