HEINONEN, R. On the pre-treatment of samples of heavy clay soil for determinations by the pressure membrane apparatus. Agricultural and Food Science, [S. l.], v. 33, n. 1, p. 153–158, 1961. DOI: 10.23986/afsci.71546. Disponível em: https://journal.fi/afs/article/view/71546. Acesso em: 20 may. 2024.