What book or books should one look into after reading the Complete Cups and Balls? Are there better books out there? Preferably that I can order on Pdf so I can enlarge the print.

Instead, how about watching tons of performances of the cups and balls from as many sources as you can find.

Reading books about the cups and balls will usually result (for most) in a very boring, overly technically-based routine with
waaaaaaaaaaaaaaay to many "phases". (Magicians love phases).

Learn the basic sleights to perfection and after that, watch as many routines as we you can.

Pick something you like.
Practice it.
Perform it.
Make it entertaining.
Reduce. Reduce. Reduce!
Add gags, bits, lines.
Make it your own.
Perform it more.
Make it more entertaining.
Reduce. Reduce. Reduce!
Add gags, bits, lines.

Rinse, repeat for years and years.

You can't learn the cups and balls simply by reading a book. As Frank has said, you must watch many routines. But you must also practice. If you want books, Go to the cups and balls museum web site and download the first chapter of Hocus Pocus, Jr. It's free. And even though the routine is very old, the advice therein is absolutely paramount to performing the cups and balls well. The author discusses timing, hand position and a number of other subjects in a very terse, effective manner that even centuries later, still hold up to scrutiny.