@article{Marron1988,
author = {Marron, J. S. and Nolan, D.},
title= {Canonical kernels for density estimation},
year = {1988},
doi = {10.1016/0167-7152(88)90050-8},
journal = {Statistics & Probability Letters},
volume = {7},
number = {3},
pages = {195--199},
}