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
Fitzwilliam Museum (Department of Manuscripts and Printed books) 1 City: Cambridge
Country: England
Folger Shakespeare Library 109 City: Washington, DC
Country: United States of America
Fondation Custodia, Frits Lugt Collection 8 Alternative names for repository: Institut NĂ©erlandais Institut Neerlandais
City: Paris
Country: France