TY  - JOUR
AU  - Huaning Liu
AU  - Wenguang Zhai
TI  - The equation $n_1n_2=n_3n_4$, the gcd-sum function and the mean values of certain character sums
JO  - Acta Arithmetica
PY  - 2012
SP  - 137
EP  - 157
VL  - 152
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/aa152-2-2/
DO  - 10.4064/aa152-2-2
LA  - en
ID  - 10_4064_aa152_2_2
ER  -