1. H. Moret and E. Louwerix, Vacuum Microbalance Techniques, Vol. 5 (K. H. Berndt, ed.), Plenum Press, New York (1965), p. 59.
2. A. J. Deruytter, J. Spaepen, and P. Pelfer, Proceedings of the 2nd Conf. on Neutron Cross Sect. and Technology, March 4–7, 1968, Washington, DC.
3. W. van der Eijk and H. Moret, Standardization of Radionuclides, I.A.E.A., Vienna (1967), p. 529.