1. F. BROWN AND C. H. WESTCOTT, Atomic Energy of Canada Limited, Chalk River, Ontario, private communication. An unpublished description of the method is contained in the report, TNCC(Can)-9 (1957).
2. Slow Neutron Resonances in Holmium, Thulium, and Lutetium
3. Thermal Neutron Activation Cross Sections
4. The enriched sample was obtained on loan from the Stable Isotopes Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee.