@article{01930056, title = {Time-symmetric cycles.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {2003}, year = {2003}, pages = {1683-1692}, doi = {10.1155/S0161171203208097}, zbl = {1016.37018}, language = {en}, url = {http://dml.mathdoc.fr/item/01930056} }
Bernhardt, Chris. Time-symmetric cycles.. International Journal of Mathematics and Mathematical Sciences, Tome 2003 (2003) pp. 1683-1692. doi : 10.1155/S0161171203208097. http://gdmltest.u-ga.fr/item/01930056/