The Shoelace Problem and Other Puzzles (Mastermind) is the second book in a series of 4 in the Mastermind Collection by one of the best Puzzle makers. Once again, Ivan has put together some old and new types of puzzles to amuse us. Along with the best friend puzzle lovers ever had, Sterling Publishing, they have put out an excellently constructed book. The paper, color and overall quality are nothing short of outstanding and appreciated. In addition to the puzzles, Moscovich scatters little mathematical tidbits throughout the book. There is so much variety in his stuff, when you finish one puzzle, it is a real treat to flip the page and face another interesting one. I tend to say to myself “That was a good one, Ivan what have you got for me now?” I not only do puzzles, I also collect them and in my library have over 500 Puzzle books which brings me to one positive criticism. Several puzzles require one to cut up the book. To me that is a total “NO-NO”. It would be so much more appreciated if those few pages that require removal were duplicated at the back and could be removed, leaving the book in tact. I am not going to describe the various types of puzzles or even pick my favorites because there are so many types and I enjoyed them all. If interested, you’ll find the Customer Review I wrote on “The Hinged Square & Other Puzzles” on April 26, 2005 among my reviews and which I also rated 5 Stars. By the way, my title was taken from the book, see if you can find where. You can purchase this book at Amazon.