2d United Nations International Conference on Peaceful Uses of Atomic Energy, Geneva, Switzerland, Sept. 1-13, 1958; [papers], U. S. A., June 1958, A/CONF.15/P/ (series). 634. Higher order differences in numerical solution of 2-dimensional neutron diffusion equations [with bibliography; by] J. A. Nohel, W. P. Timlake.