Extension activities for peanuts after rice in Ban Sum Jan, northeast Thailand a case study in farmer-to-farmer extension methodology - Jintrawet, Attachai; Smutkupt, Suriya; Wongsamun, Chaicharn; Katawetin, Roengsak; Kerdsuk, Vichein (The Farming Systems Research Project, Khon Kaen University, 1985)