pT)lv Dy VT bmg pope’ | JUL -2 1984 / f / : ~ a a a A a A 4a 4 27 sy 7 © vederberg 2- 1 THE ROCKEFELLER UNIVERSITY 1230 YORK AVENUE*> NEW YORK, N.Y. 10021 VIA AIR MAIL: Dr. J. Mayo Greenberg Professor of Laboratory Astrophysics University of Leiden Stationsweg 46, 2312 AV Leiden Netherlands ay a aa a aa a a a a A a 4