Egon Balas, Nicos Christofides. A restricted Lagrangean approach to the traveling salesman problem. Math. Program., 21(1):19-46, 1981. [doi]
@article{BalasC81,
title = {A restricted Lagrangean approach to the traveling salesman problem},
author = {Egon Balas and Nicos Christofides},
year = {1981},
doi = {10.1007/BF01584228},
url = {http://dx.doi.org/10.1007/BF01584228},
researchr = {https://researchr.org/publication/BalasC81},
cites = {0},
citedby = {0},
journal = {Math. Program.},
volume = {21},
number = {1},
pages = {19-46},
}