1. Introduction to Exchange Systems
by Flowers, T.H. 
Price: USD 107.06
Dealer: AbebooksUK, Mispah books
Description: ISBN10: 0471018651, ISBN13: 9780471018650, [publisher: John Wiley and Sons Ltd] Hardcover Dust Jacket may NOT BE INCLUDED.CDs may be missing. [Redhill, SURRE, United Kingdom] [Publication Year: 1976]  

2. Introduction to Exchange Systems
by Flowers, Thomas Harold 
Price: USD 90.00
Dealer: Abebooks, Feldman's Books
Description: ISBN10: 0471018651, ISBN13: 9780471018650, [publisher: Wiley, London] Hardcover First Edition No markings. [Menlo Park, CA, U.S.A.] [Publication Year: 1976]