@Manual{karney83a,
  author =       {Charles F. F. Karney},
  title =        {Complex Plotting and Graphics---{PLOT2}},
  organization = {The Mathlab Group, Laboratory for Computer Science,
                  M.I.T.},
  month =        jan,
  year =         1983,
  note =         {Chapter 2 of {\em {MACSYMA} Reference Manual, Version
                  10}, Vol. II, 90 pp.},
  annote =       {Earlier version appeared as Chapter 18 of Version 9;
                  First printing, July 1977; Second printing,
                  Dec. 1977},
  url =          
   {http://cvs.sourceforge.net/viewcvs.py/maxima/maxima-pre59/share/plot2.usg}
}