These textbooks in print and available here; with the exception of Press Brake Technology published by the Society of Manufacturing Engineers (SME)
Textbooks in Print includes:
Press Brake Technology A guide to precision sheet metal bending (c) 1997, Society of Manufacturing Engineers
The first complete, hardbound text on the subject of precision sheet metal bending. This hardbound textbook covers everything from the history of sheet metal forming through all of the technical information you would ever want to know, and then some.
The text, Press Brake Technology, A guide to precision sheet metal bending (c) 1997 carries with it all of the creditability of the Society of Manufacturing Engineers, which was founded in 1932 and has earned an international reputation for leadership in manufacturing technology.