Social network analysis for the assessment of pig, cattle and buffalo movement in Xayabouli, Lao PDR oleh Chaithep Poolkhet, Suwicha Kasemsuwan, Sithong Phiphakhavong, Intha Phouangsouvanh, Khamphouth Vongxay, Man Sub Shin, Wantanee Kalpravidh, Jan Hinrichs