@article{Wainer1980,
author = {Wainer, H. and Francolini, C.M.},
title= {An empirical inquiry concerning human understanding of two-variable color maps},
year = {1980},
doi = {10.1080/00031305.1980.10483006},
journal = {The American Statistician},
volume = {34},
number = {2},
pages = {81--93},
}