CAPELLA, Anna; NAVARRETTA, Valeria; GIACCHI, Elena. The Billings ovulation method: data and evaluations from the World Health Organisation multicentre study. Medicina e Morale, [S. l.], v. 32, n. 4, 2024. DOI: 10.4081/mem.1982.1541. Disponível em: https://www.medicinaemorale.it/mem/article/view/1541. Acesso em: 24 nov. 2024.