@article{1183504377,
author = {Perlin, Irwin E.},
title = {Sufficient conditions that polynomials in several variables be positive},
journal = {Bull. Amer. Math. Soc.},
volume = {48},
number = {12},
year = {1942},
pages = { 458-466},
language = {en},
url = {http://dml.mathdoc.fr/item/1183504377}
}
Perlin, Irwin E. Sufficient conditions that polynomials in several variables be positive. Bull. Amer. Math. Soc., Tome 48 (1942) no. 12, pp. 458-466. http://gdmltest.u-ga.fr/item/1183504377/