Cita APA (7th ed.)
Stanley Gibbons Publications Ltd, Bennett, R., & Watson, J. Philatelic Terms Illustrated.
Cita Chicago (17th ed.)
Stanley Gibbons Publications Ltd, Russell Bennett, i James Watson. Philatelic Terms Illustrated.
Cita MLA (9th ed.)
Stanley Gibbons Publications Ltd, et al. Philatelic Terms Illustrated.
Atenció: Aquestes cites poden no estar 100% correctes.