@article{RO_2018__52_2_439_0,
     author = {Ma, Qing-Qing and Li, Ji-Hong and Liu, Wei-Qi},
     title = {Social optimization in {M/M/1} queue with working vacation and {N-policy}},
     journal = {RAIRO - Operations Research - Recherche Op\'erationnelle},
     pages = {439--452},
     year = {2018},
     publisher = {EDP Sciences},
     volume = {52},
     number = {2},
     doi = {10.1051/ro/2017041},
     mrnumber = {3880537},
     zbl = {1401.90059},
     language = {en},
     url = {https://www.numdam.org/articles/10.1051/ro/2017041/}
}