Rainer E. Burkard, Jafar Fathali. A polynomial method for the pos/neg weighted 3-median problem on a tree. Math. Meth. of OR, 65(2):229-238, 2007. [doi]
@article{BurkardF07,
title = {A polynomial method for the pos/neg weighted 3-median problem on a tree},
author = {Rainer E. Burkard and Jafar Fathali},
year = {2007},
doi = {10.1007/s00186-006-0121-1},
url = {http://dx.doi.org/10.1007/s00186-006-0121-1},
researchr = {https://researchr.org/publication/BurkardF07},
cites = {0},
citedby = {0},
journal = {Math. Meth. of OR},
volume = {65},
number = {2},
pages = {229-238},
}