Stanley P. Y. Fung Chung Keung Poon Feifeng Zheng Online interval scheduling: randomized and multiprocessor cases. 248-262 2008 16 J. Comb. Optim. 3 http://dx.doi.org/10.1007/s10878-007-9131-z db/journals/jco/jco16.html#FungPZ08