Hughes, G E. A new introduction to modal logic / G. E. Hughes and M. J. Cresswell. - / . - London : Routledge , 2005. - x, 421p. : illus.,figs.,tables ; 23cm . Includes bibliography & index ISBN: 0415126002 GBP20.99 Subjects--Index Terms: LOGIC Dewey Class. No.: 160 / HUG/N