Williams, H. S. (1914). Twilight sleep: A simple account of new discoveries in painless childbirth. Harper.
Lua i Stíl Chicago (17ú heag.)Williams, Henry Smith. Twilight Sleep: A Simple Account of New Discoveries in Painless Childbirth. New York: Harper, 1914.
Lua MLA (8ú heag.)Williams, Henry Smith. Twilight Sleep: A Simple Account of New Discoveries in Painless Childbirth. Harper, 1914.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.