@inproceedings{hans1956a,
title={A note on the prime numbers of the forms$N$=(6$a$+1)2^{2$n$−1}−1 and$M$=(6$a$−1)2^{2$n$}−1},
author={Hans Riesel},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203420143946921},
booktitle={Arkiv for Matematik},
volume={3},
number={3},
pages={245-253},
year={1956},
}
Hans Riesel. A note on the prime numbers of the forms$N$=(6$a$+1)2^{2$n$−1}−1 and$M$=(6$a$−1)2^{2$n$}−1. 1956. Vol. 3. In Arkiv for Matematik. pp.245-253. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203420143946921.