“…In contrast, the high-order ABCs devised by Collino [4], Grote and Keller [12,13], Hagstrom and Hariharan [14] Guddati and Tassoulas [15], Givoli and Neta [16,17] and Hagstrom and Warburton [6] involve no high derivatives owing to the use of special auxiliary variables / j ðj ¼ 1; . .…”