Andersen, Dines
Copenhagen: Gyldendalske Boghandel, 1907
Buku Teks
American Psychiatric Press, 1984
Buku Referensi
Harrod, Leonard Montague
England : Gower Pub, 1987,
Buku Referensi
Buchanan, Brian
Clive Bingley & Linnet Books, 1976
Buku Referensi
Fouloy, Christian D. De.
Martinus Nijhoff Publishers, 1994
Buku Referensi