Macmillan company, 1949
Buku Teks
Blair, Walter, author
Scott-Foresman, 1946-1947
Buku Teks
Whitla, William, author
Wiley-Blackwell, 2010
Buku Referensi
edited by Albert D. Van Nostrrandvan
Books for Libraries Press, 1970
Buku Teks
Ayers, David, author
Blackwell Publishing, 2008
Buku Teks