Ensink, Jeroen H. J.; Aslam, M. Rizwan; Konradsen, Flemming; Jensen, Peter K.; Van Der Hoek, Wim(International Water Management Institute, Colombo, Sri Lanka, 2002)
Komarudin, Heru; Siagian, Yuliana L.; Oka, Ngakan Putu(CGIAR System-wide Program on Property Rights and Collective Action, International Food Policy Research Institute, Washington , DC , USA, 2007)