Fourth Workshop on Grand Unification, University of Pennsylvania, Philadelphia, April 21-23, 1983 / 
P. Langacker, P.J. Steinhardt, and H.A. Weldon, editors 
 - Boston, MA. :  Birkhauser,  1983 
 - 415 p. :  ill. ;  24 cm. 
 - Progress in physics ;  v. 9 .
<br/><br/><label>ISBN: </label>0817631690 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Grand unified theories (Nuclear physics)--Congresses<br/>Quantum gravity--Congresses<br/>Protons--Decay--Congresses<br/>Magnetic monopoles--Congresses<br/>Cosmology--Congresses