By Anderson, Nels. New York Alfred A.Knopf 1928 . 414, XII s. 21 cm.
By SUTTLES, Gerald D.. Chicago The University of Chicago Press 1971 . 243 s. 21 cm. 0-226-78192-5
Namur Presses Universitaires de Namur 1997 . 239 s. 23 cm. 2-87037-246-9
New York Routledge 2007 . XXII,567 s. 24 cm. 978-0-415-77084-2