John, Pontius, (and others)
You may find the following books of interest:
Spy Flights of the Cold War by Paul Lashmarr
Published by Sutton Publishing Ltd, 1996
ISBN 0 7509 1183 2
The author was the producer of the BBC "Timewatch" documentary "Spies in the Sky" which covered much the same ground as the book, but with interviews of some of the participants (both sides).
Shadow Flights by Curtis Peebles
Published by Presidio Press Inc, 2000
ISBN 0 89141 700 1 or 2
Covers similar ground, but with more empahasis on the U2 operations.
Finally,
The Hidden Hand by Richard J. Aldrich
Published by John Murray Ltd., 2001
ISBN 0 7195 5423 3
A mighty tome!, 645 pages, but worth a look. The book examines the workings of the intelligence community throughout the cold war and contains a few real gems.
Probably a good place to start looking for these and similar books would be on:
www.abebooks.com
Happy reading
YS