Wolff, Robert Lee
      
      
         Garland Publishing, 1981
       Buku Referensi
   
      compiled by Robert Lee Wolff
      
         Garland Publishing, 1984
       Buku Referensi
   
Karl, Frederick R.
      
      
         Farrar, Straus and Giroux, 1964
       Buku Teks SO
   
Ludlum, Robert
      
      
         Grafton, 1991
       Buku Teks SO
   
Brownings, Robert
      
      
         Everyman`s Library, 1964
       Buku Teks SO