U., Dankyarana; U.A., Umar. Assessment and Prediction of Repair and Maintenance Costs of Tractors in Northern Nigeria. Jurnal Mekanikal, [S. l.], n. 43, 2020. Disponível em: https://jurnalmekanikal.utm.my/index.php/jurnalmekanikal/article/view/396. Acesso em: 6 may. 2024.