Estimating Exact p Values by the Method of Control Variates or Monte Carlo Rescue
提出两种方法（控制变量法和蒙特卡洛救援）来更准确地估计精确p值，适用于小样本或稀疏数据的统计检验。
Pralay Senchaudhuri, Cyrus R. Mehta, Nitin R. Patel, Estimating Exact p Values by the Method of Control Variates or Monte Carlo Rescue, Journal of the American Statistical Association, Vol. 90, No. 430 (Jun., 1995), pp. 640-648