Julius
Mac Leod

Ghent University (Chemistry Tree)


Leonard Salomon
Ornstein

Utrecht (Physics Tree)


Paul
Ehrenfest

Leiden (Physics Tree)


Marcel G.J.
Minnaert

Utrecht (Physics Tree)




Anton
Pannekoek

Amsterdam








Robert Grant
Aitken

Lick Observatory


Gerard P.
Kuiper

University of Arizona





Jacob Jacco
Vink

Utrecht
(Options)

Jacob VinkX