This mammoth volume is yet another milestone in Joseph Miller's continuing survey of the ever more extensive writings on slavery around the world. From a working bibliography for a university course, this undertaking has expanded and blossomed to become this wonderful research tool for scholars, with 10,344 entries. The pervasiveness of slavery in human history is becoming ever more apparent, bringing out the peculiarity of the twentieth century. The listings include secondary scholarly works directly relevant to slavery and written from the perspective of any discipline. The framework is basically geographical by enslaving nation. The major problems here is the category ‘Muslim’, which might more fruitfully have been broken up into its constituent geographical entities. Asia, which always accounted for a far larger number of slaves than the Americas, is under-represented, in part reflecting scholarly coyness about this delicate topic. The entries are not annotated, but there are two lengthy indices, for authors and for subjects. The emphasis is on works in English, with a partial representation of writings in major West European languages. Despite these restrictions, the task is reaching the limits of the book format, as the fascination of scholars with this subject shows no sign of abating. Future editions will perhaps need to be available only in electronic format.