BibTeX
@TECHREPORT{
         Eisenpress1968ESD,
       author = "Harry Eisenpress and Abel Bomberault",
       title = "Efficient Symbolic Differentiation using {PL/I-F}ormac",
       TYPE = "Technical Report",
       institution = "IBM New York Scientific Research Center",
       ADDRESS = "Yorktown Heights, N.Y.",
       year = "1968",
       number = "320--2956",
       month = "September",
       REFERRED = "[Char1991CAa]."
}