@article{1183506230, author = {Birkhoff, Garrett}, title = {Subdirect unions in universal algebra}, journal = {Bull. Amer. Math. Soc.}, volume = {50}, number = {12}, year = {1944}, pages = { 764-768}, language = {en}, url = {http://dml.mathdoc.fr/item/1183506230} }
Birkhoff, Garrett. Subdirect unions in universal algebra. Bull. Amer. Math. Soc., Tome 50 (1944) no. 12, pp. 764-768. http://gdmltest.u-ga.fr/item/1183506230/