John and Evelyn Billings

, DCSG | image = | alt = | caption = | birth_name = Evelyn Livingston Thomas | birth_date = | birth_place = | death_date = | death_place = Melbourne, Victoria | nationality = Australian | education = | alma_mater = | occupation = Physician | years_active = | known_for = | notable_works = Jointly pioneered the natural method of family planning known as the Billings Ovulation Method }} John Billings , KC*SG (5 March 1918 – 1 April 2007) and his wife, Evelyn Livingston Billings , DCSG (née Thomas; 8 February 191816 February 2013), were Australian physicians who pioneered the natural method of family planning known initially as the Ovulation Method, then the Ovulation Method Billings, specified by the WHO in 1978 and finally as the Billings Ovulation Method. Provided by Wikipedia