I recently had the good fortune to purchase a set of three of Goldston's "Locked Books" in very good condition (thanks Pete!). They are: "Exclusive Magical Secrets", "More Exclusive Magical Secrets", and "Further Exclusive Magical Secrets". They leatherbound, and are very literally "locked books", requiring a key to unlatch them to open and read them. Since Goldston was such a prolific writer and publisher, and I am having trouble verifying whether or not I now have the complete set of his "Locked Books". Can anyone enlighten me further on this? Are there more volumes in this set?