* D. J. Bernstein, "Enumerating solutions to p(a) + q(b) = r(c) + s(d)", Mathematics of Computation 70, 233 (2000), 389—394.
)* D. J. Bernstein, "Enumerating solutions to p(a) + q(b) = r(c) + s(d)", "Mathematics of Computation" 70, 233 (2000), 389–394.