Crouch, Robert L.
Harcourt Brace Jovanovich , 1972
Buku Teks
Mundell, Robert A.
Macmillan, 1968
Buku Teks
Lieb, Robert C.
Reston Publ, 1985
Buku Teks
Kong, Robert
Jakarta Smith New Court Far East Ltd. 1994,
Buku Teks
McGee, Robert W., author
Dow Jones-Irwin , 1985
Buku Teks