@incollection{kahan:1987:bcf,
    author = {Kahan, W.},
    editor = {Iserles, A. and Powell, M. J. D.},
     title = {Branch Cuts for Complex Elementary Functions or Much Ado About
              Nothing's Sign Bit},
 booktitle = {The State of the Art in Numerical Analysis (Birmingham, 1986)},
    series = {Inst. Math. Appl. Conf. Ser. New Ser.},
    volume = {9},
     pages = {165–211},
 publisher = {Oxford Univ. Press},
   address = {New York},
      year = {1987},
   mrclass = {65E05},
  mrnumber = {MR0921666 (88k:65027)},
     zblno = {0615.65014}}