Hartman, C. G. (1962). Science and the safe period: A compendium of human reproduction. Williams & Wilkins.
Lua i Stíl Chicago (17ú heag.)Hartman, Carl Gottfried. Science and the Safe Period: A Compendium of Human Reproduction. Baltimore: Williams & Wilkins, 1962.
Lua MLA (8ú heag.)Hartman, Carl Gottfried. Science and the Safe Period: A Compendium of Human Reproduction. Williams & Wilkins, 1962.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.