@article{1183494281,
author = {Engstrom, H. T.},
title = {On the generalization of trigonometric
identities in arithmetical
paraphrasing},
journal = {Bull. Amer. Math. Soc.},
volume = {36},
number = {11},
year = {1930},
pages = { 667-672},
language = {en},
url = {http://dml.mathdoc.fr/item/1183494281}
}
Engstrom, H. T. On the generalization of trigonometric
identities in arithmetical
paraphrasing. Bull. Amer. Math. Soc., Tome 36 (1930) no. 11, pp. 667-672. http://gdmltest.u-ga.fr/item/1183494281/