Spencer, Herbert
Watts, 1937
Buku Teks
Berry, Frank
Longman , 1953
Buku Teks
Kubly, Herbert
Time-Life International , 1966
Buku Teks
Goldstein, Herbert, author
Addison-Wesley Publishing Company, INC, 1950
Buku Teks
Read, Herbert, author
Faber & Faber, 1948
Buku Teks