Todd, Lewis Paul
Harcourt Brace Jovannovich, 1972
Buku Teks
Todd, Lewis Paul
Harcourt Brace Jovanovich, 1986
Buku Teks
Curti, Merle
Harper & Brothers, 1951
Buku Teks
Todd, Paul
London Blackstone 1996.,
Buku Referensi
Alden, John Richard, author
Harper & Row Publishers, 1963
Buku Teks