This book, which can be downloaded from the Internet by clicking here, provides short descriptions of doctoral programs in several European countries, as well as a chapter on those in the United States (by Philip G. Altbach).
This is one of the Studies on Higher Education published by The European Center for Higher Education (CEPES).
A related book is:
Policy-Making, Strategic Planning, and Management of Higher Education
by John Taylor and Adrian Miroiu
CEPES Paper on Higher Education, 2002. (PDF, 184 pages.)