D. J. A. Welsh, M. B. Powell. An upper bound for the chromatic number of a graph and its application to timetabling problems. Comput. J., 10(1):85-86, 1967. [doi]
@article{WelshP67,
title = {An upper bound for the chromatic number of a graph and its application to timetabling problems},
author = {D. J. A. Welsh and M. B. Powell},
year = {1967},
doi = {10.1093/comjnl/10.1.85},
url = {https://doi.org/10.1093/comjnl/10.1.85},
researchr = {https://researchr.org/publication/WelshP67},
cites = {0},
citedby = {0},
journal = {Comput. J.},
volume = {10},
number = {1},
pages = {85-86},
}