For a property as successful and enduring as Transformers, there have been surprisingly few officially-licensed publications that catalogued the history and diversity of the franchise--and even fewer in English. Fans and publishers in the toy collecting industry have attempted to fill this gap over the years with unofficial works of varying scope, production quality, and accuracy.
Transformers: Ten-Year Retrospective
Transformers: Japanese Missions
Fanzine by Fumihiko Akiyama distributed at BotCon Japan 1997 (?). Though it's nothing compared to Akiyama's later work, it was notable in its time for being the first comprehensive checklist of Japanese TF product.
Cybertronian: The Unofficial Transformers Recognition Guide
Published by Antarctic Press from 2001-2002, Cybertronian: The Unofficial Transformers Recognition Guide is an unofficial (surprise, surprise!) but highly useful guide to American-released Transformers up to and including the first waves of Beast Wars. Although not authorised by Hasbro/Takara and thus technically a fan-publication, it was nevertheless the first book (sorta) of its kind and remains one of the most comprehensive English-language sources on the pre-Beast Era toylines of Generation One, Generation 2 and Machine Wars.
A high quality fanzine written and published by Fumihiko Akiyama in 2004, with input from Jon Hartman, Karl Hartman, and others. Written in both Japanese and English. It covers the official convention from 1994 to 2004 in both the U.S., Japan, and Europe, and includes guest interviews, event and panel summaries, and picture spreads of the events themselves and their exclusive merchandise. Its glossy, magazine-quality photo galleries are especially notable for their emphasis on the unproduced toys and concept art displayed at various conventions over the years. It is, however, worth noting that the book excludes OTFCC 2003 and 2004.
Perhaps unique among all unofficial guidebooks, Prime Targets (written by Lars Pearson, published by Mad Norwegian Press) was not meant to be a toy catalogue or retrospective, instead approaching the franchise from a story-based perspective. The book is hundreds of pages long and has almost no illustrations at all, and the very few illustrations it does have are of completely generic robotic figures, so as not to risk legal action from Hasbro. The book consisted of summaries and fan commentary of every single episode in the Generation One, Beast Wars, and Beast Machines cartoon series, and every issue of the Marvel, Marvel UK, and Blackthorne comic books. The author shows a strong and pervasive disdain for Beast Machines. Perhaps more noteworthy, the author also includes a sub-section in each episode review called "Bumpin' Bumpers," which consists of every imaginable bit of sexual innuendo that one can reference from each episode. These segments seem to have been heavily shaped by the author's wildly active imagination and, at the same time, probable unfamiliarity with the English language. For example, in the description of Five Faces of Darkness, there is a "Bumpin' Bumpers" notation that Dead End's cry "What difference does it make if death comes from the front or the rear? Death is death!" means that, since French philosophers referred to orgasm as "the little death," Dead End was talking about anal sex. No, seriously. Stranger still, there is no "Bumpin' Bumpers" segment at all for The Agenda, despite Rattrap's bold jokes about Silverbolt and Blackarachnia's "positions."
Transformers Identification and Price Guide
Developed by Krause Publications, this guide lists every American Generation One toy released from 1984-1990. Each chapter covers a year with a short intro, though the 1984 intro is longer, as it includes a section on Pre-Transformers, the 1984 overview, and the franchise's success. It then lists all of the Autobot subgroups in a somewhat random order, then the Decepticon subgroups in a similar fashion. Each character is listed in alphabetical order within its correct subgroup with its original Tech Specs and bios, as well as commentary by the author, full-color photos, and the occasional comparison (e.g., Frenzy's gold versus silver guns).
Lee's Toy Review
This magazine has published several pull-out photo guides of various American Transformer series over the years.