British Naval Post and Censor Marks of the First World War, by M H Gould.

Published by Postal History 2000, 1998.  S/B, 229pp.

This study is split into two sections - the first section covers naval postmarks, machine marks, handstamps, and received marks,and the second part deals with censors, including marks with a ship or place name, unframed marks, circular marks, oval marks, and CEN O SOR marks.  Where possible, details are given of the size and lettering type of the markings, and also of the ship/port associated with them.  Background information on fleets, battles and campaigns, naval bases and ports, and patrols is provided.  Examples of covers, postcards, letters, and cachets are illustrated in black and white.