In its day, one of the best works to appear on the subject (given that critical works on sf are very short-lived and rarely get carried forward from generation to generation in new editions). It is more of a collection of essays rather than a reference work, and so within a very short time was eclipsed by the far more detailed Peter Nicholls encyclopaedia. ( )

This is a fantastic book and a much loved one in my collection. It is really comprehensive and informative with lots of pictures and reference material. The only issue with it that I have is that I haven't been able find a later edition. This does have its benefits though as the whole book is dedicated to the classic authors of science fiction and focuses on the golden age authors. ( )

Classic compendium of chronology, genres, themes and authors, this encyclopedia will not leave you indifferent to the variety in all the subject has to offer. Bear in mind that the chronology stops at 1976, date of print. I do not know if there is a newer version, but if so, I'll get it straight away. On the same sort of book, I would also recommend Jacques Sadoul's 5-book series on the history of science-fiction, more recent and highly instructive too, despite a lesser Anglo-Saxon perspective (compared to this one). ( )

To 1976, many illustrations