Krumalova, Veronika; Backman, Stefan(Sustainable Agriculture in Central and Eastern European Countries (CEESA), Humboldt University, Berlin, Germany, 2003)
Gatzweiler, Franz W.; Backman, Stefan; Sipilainen, Timo; Zellei, Anett(Sustainable Agriculture in Central and Eastern European Countries (CEESA), Humboldt University, Berlin, Germany, 2001)