Yong Ge 0001 Hui Xiong 0001 Wenjun Zhou 0001 Ramendra K. Sahoo Xiaofeng Gao 0001 Weili Wu 0001 Multi-focal learning and its application to customer service support. 349-358 2009 KDD https://doi.org/10.1145/1557019.1557062 conf/kdd/2009 db/conf/kdd/kdd2009.html#GeXZSGW09