Collecting British Squared Circle Postmarks, by S F Cohen.

Published by S F Cohen, 2006.  S/B, 632pp.(2 Vols.)

This second edition of Stanley Cohen's catalogue of British squared circle postmarks is split into two volumes.  Part 1 explains collector terminology and establishes the types and sub-types of squared circles used in the provincial offices, and Part 2 details the types of postmarks used in the London offices, including suburban district offices.  Listings of postmarks are arranged alphabetically by post office, and information is given on earliest and latest dates used, type, proof date, series, and rarity.  Illustrated in black & white and colour.