Massachusetts Addison-Wesley , 1950
Buku Teks
Boulding, Kenneth E. (Kenneth Ewart), 1910-1993, author
Harper & Row, 1966
Buku Teks
McGraw-Hill, 1953
Buku Teks
Landauer, Carl, author
J. B. Lippincott, 1964
Buku Teks
Nevin, Edward
Macmillan ; St. Martin's Press, 1960
Buku Klasik