H. Akca1, M. Sayili1, M. Yilmazcoban2
1Gaziosmanpasa University Faculty of Agriculture, Department of Agricultural Economics 60240 Tokat, Turkey
2Ministry of Agriculture and Rural Affairs, Cinnah Street, No. 16, 06690 Kavaklidere, Ankara, Turkey
Pol. J. Environ. Stud. 2007;16(2):177–182