Hey, allaboutcircuits.com is great and has helped me tremendously as I attempt to wrap my brain around this subject. However, it appears there are some gaps which normally have text but do not in Volume III, Chapter 2, starting with the review of "Band theory of solids," and continuing through to the end of the chapter. Text is also missing from Vol. III, Chapter 3, "Clipper circuits" through "Voltage multipliers." Hope it's not permanently gone, and thanks for the great site so far!