Philosophical logic : an introduction / Sybil Wolfram. Wolfram, Sybil, 1931- Logic. BC71 .W65 1989 160 19 WOP Includes index. Bibliography: p. 263-269. London ; New York : Routledge, 1989. 1989. 1989 Text xiv, 290 p. ; http://www.loc.gov/catdir/enhancements/fy0648/88023963-d.html eng