TY  - JOUR
AU  - Luedeman, John K.
TI  - A Note on the Σ(S)-Injectivity of R(S)
JO  - Canadian mathematical bulletin
PY  - 1970
SP  - 481
EP  - 489
VL  - 13
IS  - 4
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1970-088-0/
DO  - 10.4153/CMB-1970-088-0
ID  - 10_4153_CMB_1970_088_0
ER  -