**Progress in Mathematics** 1992; 90 minutes; VHS ISBN-10: 0-8218-8066-7 ISBN-13: 978-0-8218-8066-1 List Price: US$49.95 Individual Members: US$39.96 Institutional Members: US$37.46 Order Code: VIDEO/70
| Lenstra presents a clear, well-paced, and fascinating lecture on some of the fundamental questions arising in this area. The main topic is the investigation of the multiplicative structure of rings of algebraic integers, the principal tool being a group that simultaneously describes the class group and the group of units of such a ring. It is accessible to advanced undergraduates and graduate students with backgrounds in algebra and number theory. (Orono, ME, 1991) |