Phan Phuong Loan, Nguyen Huu Yen Nhi, Tran Thi Thanh Van and Tran Phong Phu 2009  Earthworm (Perionyx excavatus) as a main protein source for growing zig-zag eel (Mastacembelus armatus) in small-household, aquaculture-based farming systems in the Mekong river delta, Vietnam. Proceedings MEKARN Workshop on  Livestock, Climate Change and the Environment (Editors: Reg Preston and Vo Lam ), An Giang University, Vietnam, 16-18 November 2009 http://www.mekarn.org/workshops/environ/Abstracts/loan.htm