Villano RA, Tran C-DTT. Technical efficiency heterogeneity of tertiary institutions in Viet Nam: a metafrontier directional technology approach. TEDE [Internet]. 2019Sep.17 [cited 2024Nov.22];25(6):1058-80. Available from: https://bme.vgtu.lt/index.php/TEDE/article/view/7452