Retail Security and Shrinkage Protection by Philip Purpura
http://www.amazon.com/Retail-Security-Shrinkage-Protection-Purpura/dp/075069274X/ref=sr_1_2?ie=UTF8&s=books&qid=1210892945&sr=8-2

Loss Prevention in the Retail Business by Rudolph C. Kimiecik and Chris Thomas
http://www.amazon.com/Prevention-Retail-Business-Rudolph-Kimiecik/dp/0471723215/ref=sr_1_1?ie=UTF8&s=books&qid=1210893287&sr=8-1

Retail Crime, Security, and Loss Prevention: An Encyclopedic Reference by Charles A. Sennewald and John H. Christman glosario
http://www.amazon.com/Retail-Crime-Security-Loss-Prevention/dp/0123705290/ref=sr_1_7?ie=UTF8&s=books&qid=1210893326&sr=8-7

The Retail Manager's Guide to Crime and Loss Prevention: Protecting Your Business from Theft, Fraud, and Violence by Liz Martinez and Liz Martinez Defranco
http://www.amazon.com/Retail-Managers-Guide-Crime-Prevention/dp/1889031666/ref=sr_1_6?ie=UTF8&s=books&qid=1210893364&sr=8-6

Shrinkage Estimation of a Linear Regression Model in Econometrics by Kazuhiro Ohtani
http://www.amazon.com/Shrinkage-Estimation-Linear-Regression-Econometrics/dp/1560728744/ref=sr_1_14?ie=UTF8&s=books&qid=1210893055&sr=8-14

Estimated inventory shrinkage is not a reserve - or is it?: An article from: The Tax Adviser by Robert E. Kempke
http://www.amazon.com/Estimated-inventory-shrinkage-not-reserve/dp/B0008YZBUM/ref=sr_1_25?ie=UTF8&s=books&qid=1210893194&sr=8-25