Even though
Programming the Z80 was not written for the TRS-80, it was one of the more popular TRS-80 programming books. I suspect that this book and
TRS-80 Assembly Language Programming by William Barden introduced more TRS-80 programmers to assembly language than any others.
The Source was a three volume set containing the complete source code of TRSDOS 6.2 (which was the same as LS-DOS 6.2). Each individual book cost $99.00, so total cost for a complete set was $297.00. Later on, these prices were heavily discounted.
