1.
Hugo Schuchardt an Graziadio Isaia Ascoli (001-B37_60)
2.
Hugo Schuchardt an Matthias de Vries (02-2)
Matthias de Vries an Hugo Schuchardt (07-12555)
Hugo Schuchardt an Matthias de Vries (17-7)
Matthias de Vries an Hugo Schuchardt (18-12562)
Maurice Wilmotte an Hugo Schuchardt (01-12802)