Dam Van Tien,  Phan Vu Hai and Le Thi Van Ha 2008 Effects of the dominance-subordinate hierarchy on recognition, acceptance and intake of agro-industrial by-products offered to animals as a supplementary feed   Proceedings MEKARN Regional Conference 2007: Matching Livestock Systems with Available Resources (Editors: Reg Preston and Brian Ogle), Halong Bay, Vietnam, 25-28 November 2007 http://www.mekarn.org/prohan/tien.htm