1、【题 名】：A Note on Optimal Matching With Variable Controls Using the Assignment Algorithm
【作 者】： Kewei Ming and Paul R. Rosenbaum
【年, 卷(期), 起止页码】：Journal of Computational and Graphical Statistics. September 1, 2001, 10(3): 455-463
【全文链接】：http://www.jstor.org/pss/1391099

2、【题 名】：Optimal Matching for Observational Studies
【作 者】： Paul R. Rosenbaum
【年, 卷(期), 起止页码】：Journal of the American Statistical Association  Vol. 84, No. 408 (Dec., 1989), pp. 1024-1032

【全文链接】：http://www.jstor.org/pss/2290079