@article{1183493288,
author = {Lehmer, D. H.},
title = {On the number ${{\left( {10^{23} - 1} \right)} \mathord{\left/
{\vphantom {{\left( {10^{23} - 1} \right)} 9}} \right.
\kern-\nulldelimiterspace} 9}$},
journal = {Bull. Amer. Math. Soc.},
volume = {35},
number = {6},
year = {1929},
pages = { 349-350},
language = {en},
url = {http://dml.mathdoc.fr/item/1183493288}
}
Lehmer, D. H. On the number ${{\left( {10^{23} - 1} \right)} \mathord{\left/
{\vphantom {{\left( {10^{23} - 1} \right)} 9}} \right.
\kern-\nulldelimiterspace} 9}$. Bull. Amer. Math. Soc., Tome 35 (1929) no. 6, pp. 349-350. http://gdmltest.u-ga.fr/item/1183493288/