Clark, David, 1946-, author
Routledge, 1996
Buku Teks
Gleeson, Brendan, 1964- author
Routledge, 2014
Buku Teks
Newland, Kathleen, author
Worldwatch Institute, 1980
Buku Teks
M.I.T. Press and Harvard University, 1963
Buku Teks
Bergel, Egon Ernest, author
McGraw-Hill, 1955
Buku Teks