@article{1077489912,
author = {Carlitz, Leonard},
title = {Sums of squares of polynomials},
journal = {Duke Math. J.},
volume = {3},
number = {1},
year = {1937},
pages = { 1-7},
language = {en},
url = {http://dml.mathdoc.fr/item/1077489912}
}
Carlitz, Leonard. Sums of squares of polynomials. Duke Math. J., Tome 3 (1937) no. 1, pp. 1-7. http://gdmltest.u-ga.fr/item/1077489912/