Grigg, David, author
Routledge, 1995
Buku Teks
Singh, Jasbir, author
Tata McGraw-Hill, 1984
Buku Teks
Getis, Arthur, author
McGraw-Hill Higher Education, 2009
Buku Teks
Kendall, Henry M., author
Harcourt, Brace, 1958
Buku Teks
Getis, Arthur, author
McGraw-Hill, 2000
Buku Teks