Ross, Robert C., author
McGraw-Hill, 1951
Buku Teks
Thomson, Edgar
Thomson Nelson and Sons Ltd. , 1949
Buku Teks
Slavin, Stephen, author
Richard D. Irwin, 1991
Buku Teks
Morgan, Theodore, author
Prentice-Hall, 1950
Buku Teks
Cairncross, Alec, author
Butterworth, 1960
Buku Teks