T. Cochrane et Zy. Zheng, SMALL SOLUTIONS OF THE CONGRUENCE 1)(2)-P)(A(2)X(2)(2)+A(3)X(3)(2)+A(4)X(4)(2)C(MOD), Acta Mathematica Sinica, New Series, 14(2), 1998, pp. 175-182
For any integers a(1), a(2), a(3), a(4) and c with a(1)a(2)a(3)a(4) no
t equal 0(mod p), this paper shows that there exists a solution X = (x
(1), x(2), x(3), x(4)) is an element of Z(4) of the congruence a(1)x(1
)(2) + a(2)x(2)(2) + a(3)x(3)(2) + a(4)x(4)(2) = c(mod p) such that \\
X\\ = max{\x(1)\i, \x(2)\, \x(3)\, \x(4)\} much less than root p log p
.