Zenber, Helmut
Darmstadt : und Neuwied Hermann Luchterhand, 1973
Buku Teks
Stutterheim, Willem Frederik, 1892-1942, author
De Bliksem, 1929
Buku Teks
Humanist, 2010
Buku Teks
Hoffding, Harold, author
Macmillan, 1955
Buku Teks
Berndt, Ronald M., author
University Microfilms International, 1954
Buku Teks