These are scans of the Apple Business BASIC Reference Manuals, Volumes 1 and 2. This was a version of BASIC for the Apple III. The sources for these scans aren’t the best; Volume 1 has been marked up with permanent maker, though all the text is still completely readable; and the front cover of volume 2 is so badly damaged, it was unfit for scanning purposes.
Additionally, Apple decided to print the page numbers as black text on a dark brown bar at the top of each page, making capture in black and white impossible. I did add bookmarks to the PDFs for chapter and major section headings, so you should still be able to find what you’re looking for without too much trouble.