@article{bwmeta1.element.bwnjournal-article-doi-10_4064-aa152-2-2,
author = {Huaning Liu and Wenguang Zhai},
title = {The equation n1n2 = n3n4, the gcd-sum function and the mean values of certain character sums},
journal = {Acta Arithmetica},
volume = {155},
year = {2012},
pages = {137-157},
zbl = {1315.11082},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-aa152-2-2}
}
Huaning Liu; Wenguang Zhai. The equation n₁n₂ = n₃n₄, the gcd-sum function and the mean values of certain character sums. Acta Arithmetica, Tome 155 (2012) pp. 137-157. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-aa152-2-2/