@inproceedings{m.1980minimal,
title={Minimal triangulations on orientable surfaces},
author={M. Jungerman, and G. Ringel},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203252460021282},
booktitle={Acta Mathematica},
volume={145},
number={1},
pages={121-154},
year={1980},
}