Flippo, Edwin B., author
McGraw-Hill Kogakusha, 1976
Buku Teks
Northcott, C.H.
Philoshopical Library , 1956
Buku Teks
Scott, Walter Dill, author
McGraw-Hill, 1959
Buku Teks
Flippo, Edwin B., author
McGraw-Hill, 1984
Buku Teks
Heckman, I. L., author
Charles E. Merrill, 1962
Buku Teks