Karasek, Hellmuth
Friedrich Verlag, Velber, 1966
Buku Teks
Niematz, Max
De Arbeiderspers, 1991
Buku Teks
Apel, Max, 1869-1945, author
Berlin : Walter de Gruyter, 1958
Buku Referensi
Toon Vugts [and others]
UvA Erfgoedlab, 2011
Buku Teks
[publisher not identified], [date of publication not identified]
Buku Teks