Miklós Ajtai Nimrod Megiddo Orli Waarts Improved Algorithms and Analysis for Secretary Problems and Generalizations. 1-27 2001 14 SIAM J. Discrete Math. 1 http://epubs.siam.org/sam-bin/dbq/article/29001 db/journals/siamdm/siamdm14.html#AjtaiMW01