edited by C. J. Allegre and S. R. Hart. edited by J. A. Bondy, U. S. R. Murty. edited by J. A. Bondy, U. S. R. Murty edited by I. M. Allison and C. Ruiz. edited by J.C. Allen and R.J. Hamilton. edited by I. R. Hill and S. J. L. Wright. edited by F. W. A. Hobart. edited by C. W. White, P. S. Peercy edited by Y. Alavi and D. R. Lick. edited by J. W. S. Hearle and L. W. C. Miles.