Lee J. White, Mark L. Gillenson. k-covers in weighted graphs. Math. Program., 8(1):20-42, 1975. [doi]
@article{WhiteG75, title = {k-covers in weighted graphs}, author = {Lee J. White and Mark L. Gillenson}, year = {1975}, doi = {10.1007/BF01580426}, url = {http://dx.doi.org/10.1007/BF01580426}, researchr = {https://researchr.org/publication/WhiteG75}, cites = {0}, citedby = {0}, journal = {Math. Program.}, volume = {8}, number = {1}, pages = {20-42}, }