1. Agribusiness Study Program, Department of Agriculture, Faculty of Animal and Agricultural Sciences Universitas Diponegoro Indonesia, Jl. Prof. Soedarto, S.H., Tembalang, Semarang
2. Directorate General of Plantation Ministry of Agriculture Republic Indonesia Jl. Harsono RM. No. 3 Ragunan Jakarta Indonesia
3. Agribusiness Study Program, Department of Agriculture, Faculty of Animal and Agricultural Sciences Universitas Diponegoro Indonesia, Jl. Prof. Soedarto, SH., Tembalang, Semarang Indonesia