This book is a volume in the Penn Press Anniversary Collection. To mark its 125th anniversary in 2015, the University of Pennsylvania Press rereleased more than 1,100 titles from Penn Press's distinguished backlist from 1899-1999 that had fallen out of print. Spanning an entire century, the Anniversary Collection offers peer-reviewed scholarship in a wide range of subject areas.

This "work is organized by subject. Materials are grouped under twelve main sections in the body of the work, with appropriate subdivisions and subtopics within each main subject. Each section is assigned a two-letter designation, and entries are numbered consecutively within each section. This subject code system was designed to facilitate referals from the Index to the main body of the text, and to allow for cross-referencing between sections."--Introduction.