@article{RO_2021__55_S1_S571_0,
     author = {Khezri, Somayeh and Dehnokhalaji, Akram and Hosseinzadeh Lotfi, Farhad},
     title = {A full investigation of the directional congestion in data envelopment analysis},
     journal = {RAIRO. Operations Research},
     pages = {S571--S591},
     year = {2021},
     publisher = {EDP-Sciences},
     volume = {55},
     doi = {10.1051/ro/2019092},
     mrnumber = {4223084},
     language = {en},
     url = {https://www.numdam.org/articles/10.1051/ro/2019092/}
}