On Sums Of Coefficients Of Maass Forms For SL(3, ℤ)

Let f be a Maass form for
$SL(3,{\mathbb{Z}})$
with coefficients A
f
(m, n). The aim of this paper is to study the asymptotic behaviour of the sum
$\sum_{m\leqslant x,n\leqslant y}|A_f(m,n)|^2$
and some other related sums.