The Alphabetic Labyrinth is a prime example of how *not* to research a book. Like the late E A Wallis Budge, Drucker has a habit of not double checking a source's facts; thus we're told that Ogham is a "Welsh" alphabet (it's an Irish cipher), that Runes and Ogham have never been found in the same area - never mind the same monument - (So what's the famous Killaloe Rune/Ogham Stone then; Irish mist?), and the "Roger Bacon Cipher" (better known as the Voynich Manuscript) was deciphered by Prof Leonell Strong (his 'decipherment' was discredited decades ago; The Voynich Manuscript remains undeciphered to this day).
Historical personalities suffer from factual errors too. There are too many to mention them all but a typical example is Drucker telling the reader that Charlemagne's "illiteracy" is a "well established fact"; whereas his contemporary biographer, Alcuin of York, did say that Charlemagne never mastered his letters, but he also said Charlemagne could "speak Latin and read Greek": Dyslexic maybe, but illiterate; an opinion at best and most certainly not a well established fact.
Drucker doesn't double check her sources so their mistakes become hers, and as a result everything she says must be taken with a large dose of scepticism. This is a pity, not only because of the book's first class typography and excellent illustrations, but also because of the sections on the more esoteric and occult uses of alphabets are very interesting indeed, and Drucker is a good writer who's enthusiasm is put across with clarity and wit. In spite of its failings it is a very good and entertaining read, and worth buying for that alone - but alas not to be trusted in its conclusions, facts, or used as an authoritive reference work.
For the amateur who won't know where Drucker is (or rather her sources are) in error, the Alphabetic Labyrinth can only mislead them. Personally, I'd recommend the works of Andrew Robinson and The British Library's "Reading the Past" series for those beginning their study of the alphabet and ancient western writings systems, and the works of R I Page for those particularly interested in Runes (all available from Amazon). Unfortunately I know of no other modern work specifically covering the esoteric and occult uses of alphabets, and the student will have to glean that information from more general works on topics such as alchemy, witchcraft, secret societies, and the kabbalah.