The Postal History of Ceylon, by E B Proud.

Published by Proud-Bailey, 2006.  H/B, 936pp.

Detailing: 1) The General History, 2) The Postal History, 3) The Postal Rates with tables, etc, 4) The Post Offices and Postmarks, 5) Travelling Post Offices, 6) The Edwardian Double-Circle Postmarks of Ceylon and Office Status, and 7) Censorship.  With valuations for cancels on stamps and covers, Earliest and latest dates of the use of cancels, etc.  Profusely illustrated.