BICHMANN, Mathias. Trächtigkeitsdiagnose per Ultraschall. agricultural engineering.eu, [S. l.], v. 52, n. 4, p. 196–197, 1997. DOI: 10.15150/lt.1997.2614. Disponível em: https://www.agricultural-engineering.eu/landtechnik/article/view/1997-52-4-196-197. Acesso em: 29 apr. 2024.