Wallacem W. Stewart
Macmillan, 1945
Buku Teks
Victoria Neufeldt, Andrew N. Sparks, editor
Simon & Schuster, 1989
Buku Referensi
Ricky Ganang, 1951-, author
National department for culture & Arts, 2009
Buku Referensi
Wortabet, John, author
Frederick Ungar Publishing, 1954
Buku Referensi
Scotland, 1999
Buku Referensi