Further reading
* Gibbons-Partridge, J. "Line-Engraved Colours and the 'Penny Blue'". ''The GB Journal''. Vol. 32 No. 4 (September 1994), p. 78-80. * Worsfold, Peter. "Penny Red and Penny Blue Revisited". ''The GB Journal''. Vol. 32 No. 2 (May 1994), p. 36-38. Postage stamps of the United Kingdom Cultural depictions of Queen Victoria