BibTex format
@article{PRETZEL:1987:10.1016/0012-365X(87)90012-4,
author = {PRETZEL, O},
doi = {10.1016/0012-365X(87)90012-4},
journal = {DISCRETE MATHEMATICS},
pages = {241--244},
title = {A NON-COVERING GRAPH OF GIRTH 6},
url = {http://dx.doi.org/10.1016/0012-365X(87)90012-4},
volume = {63},
year = {1987}
}