Note: every manifestation of a letter is counted, so the number of documents in a repository may be larger than the number of letters.

Repository Number of documents Further details
Oddělení pro studium a edici díla J.A. Komenského, Filosofický ústav AVČR 6 City: Praha
Alternative names for city: Prague
Country: Czech Republic
Oesterreichische Nationalbibliothek 300 Alternative names for repository: Österreichische Nationalbibliothek Austrian National Library Osterreichische Nationalbibliothek
City: Vienna
Alternative names for city: Wien
Country: Austria
Oxford University Archives 111 City: Oxford
Country: England, United Kingdom