I've been a fan of Nikoli puzzles since discovering them through the US Puzzle Championship exam years ago. I always wanted more practice but had a hard time finding paper puzzle books to work with. Especially if I didn't want a book with Sudoku. Anyhow, just a few months ago, I discovered two puzzles books at Barnes and Noble!
https://www.barnesandnoble.com/w/iq-puzzles-1-nikoli/1131029... https://www.barnesandnoble.com/w/iq-puzzles-2-nikoli/1131029...