Xuanzang, by Sally Hovey Wriggins 1996 WestviewPress, ISBN 0813334071. A great general resource, and the most approachable, of anything on Xuanzang. It has a superb bibliography

In the Footsteps of the Buddha, Rene Grousset 1932 Routeledge and Kegan Paul.. Out of print, but if you can get this from a library, it really has excellent information on Xuanzang, the region and the period.

Journey to the West, translated by Anthony Yu 1977 University of Chicago. 4 volume set, ISBN 0226971503

Sir Aurel Stein, by Jeanette Mirsky, 1977 University of Chicag0, ISBN 0226531767

Empire of the Steppes, A History of Central Asia, Rene Grousset, 1970 Rutgers University ISBN 0813513049

Buddhist Records of the Western World, 1884, 1994 Samuel Beal, Motilal Banarsidass ISBN 8120811070

A Record of Buddhist Kingdoms, James Legge, 1965 Clarendon Press, Dover Publications

In the Footsteps of the Buddha, An Iconic Journey from India to China 1998, University of Hong Kong. This book, available only from Hong Kong is a must havefor anyone interested in Buddhist art.

A Biography of the Tripitika Master of the Great Ci'en Monastery of the Great Tang Dynasty, by Sramana Huili, translated by Li Rongxi 1995 Numata Center for Buddhist Translation and Research, ISBN 1886439001. This is the official biography writtn by Xuanzang's student.

Pakistan Handbook, Isobel Shaw. 1998, Moon Publications. Besides being the best guidebook on Pakistan, she includes lots of information on the Buddhist sites throughout the country.

The Silk Road, Judy Bonavia, 1999 Odyssey Communications. A good guide for the China part of the silk road. Also, see the book below., These are good compliments to eachother.

The Silk Routes, Peter Neville Hadley 1997 Globe Pequot, ISBN 1860110525

Foreign Devils on the Silk Road, Peter Hopkirk. ISBN: 0870234358 . About the turn of the century explorers. Reads like an Indiana Jones movie. Great stuff.

The following books by Sir Aurel Stein: Ancient Khotan, On Ancient Central Asian Tracks, Ruins of Desert Cathay, Serendia

This is a very partial list, though you can email me any suggestions