TY  - BOOK
AU  - Ross,Ralph Gilbert
TI  - Obligation: a social theory 
SN  - 0472087657 :
U1  - 301 
PY  - 1970///
CY  - Ann Arbor, Mich.
PB  - University of Michigan Press
KW  - Ethics
KW  - Social ethics
KW  - Duty
ER  -