Urkunden Prüfvereinigung: Sonstiges

Prüfer	Art des Attestes	Katalog	KatalogNr.
Sydney Philatelic Research, Drury, Michael (Sonstiges)	Attest	Stanley Gibbons	21
Simmermacher, René (Sonstiges)	Befund	Stanley Gibbons	21
The One Cent Franklin Plating Archive, Richard Doporto (Sonstiges)	Attest	Scott	21
Boškovič, Zoran (Sonstiges)	Attest	Michel	21
Bühler, Georg (Sonstiges)	Attest	Michel	21 a
Bühler, Georg (Sonstiges)	Attest	Michel	21 a
Raybaudi, Maurizio (Sonstiges)	Sonstiges	Sassone	21 b
Simon, Joachim (Sonstiges)	Attest	Michel	21 bl