The Plating of the penny 1840-1864 a tabulation of the measured positions of the check letters and other relevant data arranged for easy plate identification
Brown, Roland.
Fisher, Harold W.(Harold Wolf),1903-
Saffron Walden Published for the Great Britain Philatelic Society by G.B. Philatelic Publications Ltd,
c1984
Bibliography: p753
G.B.P.S. line-engraved plating gauge (1 photo. : b & w : 85x65mm) in pocket
Postage stamps
Postage-stamp printing