ABSTRACT
The following bibliographical essay, like those appended to companion volumes in this series, relies heavily on works available in English but extends to titles in other languages wherever and whenever their intrinsic importance appears to justify such inclusion. In keeping with series policy, the bibliography has been divided by headings which correspond to chapter titles employed in the text. Some of the books or articles mentioned here have already been cited in endnotes. A number of the more specialized footnote references, however, are not repeated, for what I hope the reader will recognize as sensible reasons.
