TY  - BOOK
AU  - Hughes,George Edward
AU  - Cresswell,M.J.
TI  - A new introduction to modal logic
SN  - 9780415126007
U1  - 160 
PY  - 1996///
CY  - London
PB  - Routledge
KW  - Modality (Logic)
N1  - Includes bibliographical references and index
ER  -