@article{1183743417,
author = {Marker, D. and Pillay, A.},
title = {Reducts of $(C, +, \cdot)$ which Contain +},
journal = {J. Symbolic Logic},
volume = {55},
number = {1},
year = {1990},
pages = { 1243-1251},
language = {en},
url = {http://dml.mathdoc.fr/item/1183743417}
}
Marker, D.; Pillay, A. Reducts of $(C, +, \cdot)$ which Contain +. J. Symbolic Logic, Tome 55 (1990) no. 1, pp. 1243-1251. http://gdmltest.u-ga.fr/item/1183743417/