Cita APA (7th ed.)
Stanley Gibbons Publications Ltd & Allen, E. Collect British Stamps: A Stanley Gibbons Checklist of the Stamps of Great Britain (Vigésima edición.).
Cita Chicago (17th ed.)
Stanley Gibbons Publications Ltd i Eric Allen. Collect British Stamps: A Stanley Gibbons Checklist of the Stamps of Great Britain. Vigésima edición.
Cita MLA (9th ed.)
Stanley Gibbons Publications Ltd i Eric Allen. Collect British Stamps: A Stanley Gibbons Checklist of the Stamps of Great Britain. Vigésima edición.
Atenció: Aquestes cites poden no estar 100% correctes.