Kevin J. Avery, American Drawings and Watercolors in the Metropolitan Museum of Art, Metropolitan Museum of Art, (ISBN978-1-58839-060-8, lire en ligne), p. 297
Denmark, Danish Ministry for Foreign Affairs and the Danish Statistical Department, (lire en ligne), p. 578
denstoredanske.dk
"Philip Weilbach", Dansk Biografisk Leksikon; retrieved 8 October 2012 (in Danish language).