Pathfinders 2: Wilhelm Hillebrand, First Teacher of the Sympto-Thermic Method (1979)

Pathfinders 2: Wilhelm Hillebrand, First Teacher of the Sympto-Thermic Method by Rudolf F. Vollman, a consultant, Human Reproductive Section, World Health Organization, former head, Section on Obstetrics, Perinatal Research Branch, National Institute of Neurological Diseases and Blindness, Bethesda, Maryland.

This article from the International Review of Natural Family Planning, Vol. III, Number 4, Winter 1979, discusses the pioneering work of Wilhelm Hillebrand in Natural Family Planning.

This classic article discusses the pioneering work of Wilhelm Hillebrand in Natural Family Planning.