Keith J. Devlin. A note on a problem of Erdös and Hajnal. Discrete Mathematics, 11(1):9-22, 1975. [doi]
@article{Devlin75,
title = {A note on a problem of Erdös and Hajnal},
author = {Keith J. Devlin},
year = {1975},
doi = {10.1016/0012-365X(75)90101-6},
url = {http://dx.doi.org/10.1016/0012-365X(75)90101-6},
researchr = {https://researchr.org/publication/Devlin75},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics},
volume = {11},
number = {1},
pages = {9-22},
}