Hong Kong, The Postal History Society, 1960 (Edition limited to 500 copies for sale). 1 volume, soft printed blue covers, stapled, with paper spine, 37 pp., a good and clean copy.
A comprehensive guide to scarcity published as a Supplement to the classic handbook on the postage stamps and postal history of Hong Kong and the Treaty Ports. "Philatelic and Postal History of Hong Kong and the Treaty Ports of China and Japan", written and published by the same author.