Edited by C. B. van Turnhout. edited by P. W. J. van Rensburg. edited by A.O. Barut. edited by M.L. van Beusichem. edited by A. van Itterbeek. edited by E. van Oye. edited by G.A. Kerkut. edited by Han van Dop. edited by L. T. Evans. edited by Woutera van Iterson.