Hewlett, M.R., Picton's Philatelic Handbook No. 1, A Provisional G ...Hewlett, M. R., Picton's Philatelic Handbook No. 1, A Provisional Guide to the Valuation of the Numeral Cancellations of the British Isles, Part 1 England and Wales (with Used Abroad, Channel Islands and Isle of Man.) and Hewlett's Aligning Code as applicable to all Postal Markings, 1979, 77 S., mit einigen Abb. #62986