H. Luo, R. Shen, C. Niu, and C. Ullrich. Proceedings of the 14th International Conference on Artificial Intelligence and Statistics (AISTATS), 15, page 470--478. (2011)
C. Ullrich, J. Wang, R. Shen, and F. Quosdorf. International Conference on Artificial Intelligence and Computational Intelligence, 4, page 510--514. Los Alamitos, CA, USA, IEEE Computer Society, (2009)