H. A. Tasman and A. J. H. Boerboom, Elimination of the radial second order angular aberrations in inhomogeneous field mass spectrometers by inclined plane boundaries, Z. Naturforsch. Teil A 15, 736-738 (1960)
P. K. Rol, J. M. Fluit, F. P. Viehb and M. R. de Jong: Sputtering of copper-monocrystals by bombardment with 20 keV Ar+In: Proceedings of the Fourth International Conference on Ionization Phenomena in Gases, Uppsala 17-21 August 1959 /ed. N. R. Nilsson, North-Holland, 1960. - pp. 257-259
T. J. M. Sluyters, Inelastische botsingen tussen Ar+ ionen of Ar atomen en de gasmolekulen H2, He, Ne, Ar, Kr en Xe in het energiegebied van 5-24 keV, University of Amsterdam, 1959-07-08