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Friedrich
Schlemm

Universität Berlin







Johan Frans
van Bemmelen

RUG
(Options)

Albert Egges
van Giffen

RUG (History of History Tree)

W. J.A.
Willems

(History of History Tree)

Pieter J. R.
Modderman

University of Groningen, Leiden University (History of History Tree)

Harm Tjalling
Waterbolk

RUG (History of History Tree)

Willem
Glasbergen

Amsterdam (History of History Tree)

Johan van BemmelenX