"For an hexagonal planform in a semi-space a > 0, -oo 3 y < co, bounded by a
rigid wall, a = 0, consider that the ... j = 0, 1, 2 in Eqs (4.70) as Ao = F(a, t), A1 =
A2 = G(a, t), where F(a, t) is the complex amplitude of the system of rolls with the ..."