J.E. KAUFMANN is a retired public school teacher and has written several books on fortifications.He is founder of SITE O, an international research group consisting of enthusiasts and experts in the field of fortifications.
CLAYTON DONNELL recently retired from the U.S. Air Force. He spent several years in Europe doing field research on the Maginot Line and other French fortification systems. In 1996 he created one of the first internet sites in the world devoted to the Maginot line. He is an avid military historian and is especially versed in the period of the European conflicts from 1870 to 1945.