Arjen Markus This classical, even seminal book on testing techniques concentrates on the whitebox approach. A heavy volume stuffed with details, but a must for any one who takes the job seriously.
Title: Software Testing Techniques Author: [Boris Beizer] Publisher: Van Nostrand Reinhold, New York Edition: second Publication date: 1990
As a personal note: This was the book that told me Tcl exists and how wonderful it is in a testing context.
[Good write-up, Arjen.]