The Time Machines by Mike Ashley
This first volume in Mike Ashley's Magnum Opus, 'The History of the Science Fiction Magazine' (the final volume is still to be published) is a completely rewritten and expanded version of his earlier history published in the mid ‘70s.
The earlier work could be classed as part anthology, as it contained actual stories of historical significance, along with in-depth introductions. This first volume in the new series does away with the stories themselves and concentrates on the history of the magazines, along with the writers, editors and publishers who were responsible for SF's Golden Age up to 1950.
Written in an easy to read style, the book is packed with information, including appendices covering non-English language magazines, publishers and editors, cover artists and, of course, a summary of the magazines themselves, showing publication dates and editors/publishers.
Highly recommended to pulp magazine collectors or anyone interested in science fiction history (if you can get hold of a copy — the book is currently out of print and is next to impossible to find in the usual second-hand outlets).