Gatzweiler, Franz W.; Backman, Stefan; Sipilainen, Timo; Zellei, Anett(Sustainable Agriculture in Central and Eastern European Countries (CEESA), Humboldt University, Berlin, Germany, 2001)
Wittmer, Heidi; Birner, Regina(CGIAR System-wide Program on Property Rights and Collective Action, International Food Policy Research Institute, Washington, DC, 2005)