Cita APA (7a ed.)
Tyler, V. E. Focus on Forgeries: A Guide to Forgeries of Common Stamps.
Cita Chicago Style (17a ed.)
Tyler, Varro E. Focus on Forgeries: A Guide to Forgeries of Common Stamps.
Cita MLA (9a ed.)
Tyler, Varro E. Focus on Forgeries: A Guide to Forgeries of Common Stamps.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.