TY - BOOK AU - Green,M. AU - Lengo,R. AU - Randjbar-Daemi,S. AU - Sezgin,E.and AU - Strominger,A. TI - Superstrings '89. Proceedings of the Trieste Spring School, 3-14 April 1989 SN - 9810201389 PY - 1990/// CY - Singapore PB - World Scientific ER -