Pierre Fraisse, Oscar Ordaz. A Chvátal-Erdös condition for (t, t)-factors in digraphs using given arcs. Discrete Mathematics, 71(2):143-148, 1988. [doi]
@article{FraisseO88,
title = {A Chvátal-Erdös condition for (t, t)-factors in digraphs using given arcs},
author = {Pierre Fraisse and Oscar Ordaz},
year = {1988},
doi = {10.1016/0012-365X(88)90067-2},
url = {http://dx.doi.org/10.1016/0012-365X(88)90067-2},
researchr = {https://researchr.org/publication/FraisseO88},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics},
volume = {71},
number = {2},
pages = {143-148},
}