This DCE is Distributed Computing Environment (for UNIX). The book is volume 2 of a two volume set. It contains threads, distributed time services and security services. Volume one contains routines, RPC, and directory services. I would assume that you will want both books and assume that volume one will cost the same as volume 2. (It is strange that volume 2 was sent for review without volume 1)
Apart from a two page introduction the rest of the book describes the function calls rather like a UNIX man page or the Borland Windows API Reference. If you use the DCE library this book will be essential (if you don’t have a reference) otherwise it is of little use. It is not a readable book from which to learn DCE. There are the odd half page code examples but not enough to warrant a disk. If I was programming in this area I would want both volumes to hand.