OKSANEN, E. H. Maataloustraktorien kunnossapitokustannuksesta. Agricultural and Food Science, [S. l.], v. 28, n. 1, p. 248–256, 1956. DOI: 10.23986/afsci.71405. Disponível em: https://journal.fi/afs/article/view/71405. Acesso em: 12 apr. 2025.