麻烦哪位前辈帮忙下3篇论文，非常感谢您！
1.Nonparametric probability density estimation EJ Wegman - Journal of Statistical Computation and Simulation, 1972 - Taylor & Francis
2.Nonparametric Probability Density Estimation: I. A Summary of Available Methods
Edward J. Wegman ，Technometrics，Vol. 14, No. 3 (Aug., 1972), pp. 533-546
(article consists of 14 pages)
3.Nonparametric probability density estimation: II. A comparison of density estimation methods ，EJ Wegman - Journal of Statistical Computation and Simulation, 1972