Xue, G.-R.; Zeng, H.-J.; Chen, Z.; Yu, Y.; Ma, W.-Y.; Xi, W. & Fan, W. (2004), Optimizing web search using web click-through data, in 'CIKM '04: Proceedings of the thirteenth ACM international conference on Information and knowledge management' , ACM, New York, NY, USA , pp. 118--126 .