Linda Valdes. On the divisibility of the cycle number by 7. Discrete Mathematics, 120(1-3):301-305, 1993. [doi]
@article{Valdes93,
title = {On the divisibility of the cycle number by 7},
author = {Linda Valdes},
year = {1993},
doi = {10.1016/0012-365X(93)90592-H},
url = {http://dx.doi.org/10.1016/0012-365X(93)90592-H},
researchr = {https://researchr.org/publication/Valdes93},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics},
volume = {120},
number = {1-3},
pages = {301-305},
}