Additional information on these and other puzzle books is available in the article "What's Missing?" Puzzle and Poster Series in Over 60 Languages! Readers who are interested in the series may also enjoy the book Alphabets of the World: Letters from 78 Languages, which presents alphabets from around the world in clear format for easy comparison.
With Kindle Unlimited ($9.99/month) at Amazon.com, you can read all e-books from Schottenbauer Publishing for no extra charge! Amazon offers Free 30 Day Trials of Kindle Unlimited. With this deal, trial members can read all Schottenbauer Publishing e-books free! This includes all the e-book puzzles, Alphabets of the World, The World in a Graph, all the geometry workbooks, the books on Bow Science & Exercises, and the educational novels by M. Schottenbauer, Ph.D. Currently, Kindle Unlimited is available in the USA and UK, with expansion to other countries expected soon.