@techreport{lehman:1973:gra,
    author = {Lehman, D. R. and O'Connell, J. S.},
     title = {Graphical Recoupling of Angular Momenta},
institution = {National Bureau of Standards},
      note = {Monograph 136},
 publisher = {U.S. Government Printing Office},
   address = {Washington, D.C.},
      year = {1973}}