@article{ZNSL_1980_98_a6,
     author = {I. A. Ibragimov and R. Z. Khas'minskii},
     title = {Estimation of distribution density},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {61--85},
     publisher = {mathdoc},
     volume = {98},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1980_98_a6/}
}