Bonger, Criminalité et Conditions Economiques, 1905, pp. 378-414.
La Donna Delinquente, p. 401.
Raciborski, Traité de l'Impuissance, p. 20. It may be added that Bergh, a leading authority on the anatomical peculiarities of the external female sexual organs, who believe that strong development of the external genital organs accompanies libidinous tendencies, has not found such development to be common among prostitutes.