Efficiency Scores Analysis of Coal Mines using IRS, DRS and Cross Efficiency Models. Journal of Advance Research in Mechanical and Civil Engineering (ISSN: 2208-2379), [S. l.], v. 2, n. 2, p. 01–07, 2015. DOI: 10.53555/nnmce.v2i2.367. Disponível em: https://jarmce.com/index.php/mce/article/view/7. Acesso em: 22 aug. 2025.