Transactions of the International Astronomical Union, Vol. XVIA, reports on Astronomy: Edited by G. Contopoulos. Reidel, Dordrecht, Holland, 1976. Part 1, pp. 228, Dfl. 90 (US $33). Part 2, pp. 240, Dfl. 90 (US $33). Part 3, pp. 222, Dfl. 90 (US $33)