@article{1138036120,
author = {Nickel, Paul A.},
title = {A biharmonic normal operator},
journal = {Kodai Math. J.},
volume = {3},
number = {1},
year = {1980},
pages = { 59-69},
language = {en},
url = {http://dml.mathdoc.fr/item/1138036120}
}
Nickel, Paul A. A biharmonic normal operator. Kodai Math. J., Tome 3 (1980) no. 1, pp. 59-69. http://gdmltest.u-ga.fr/item/1138036120/