edited by I. Livingstone
Penguin Books, 1971
Buku Teks
edited by David Pettit and Anne Hall
Victoria Sorret, 1978
Buku Teks
Spengler, Joseph J. (Joseph John), 1902-1991, author
The Free Press of glencoe, 1963
Buku Teks
Sorrett, 1977
Buku Teks
edited by Kenneth J. Arrow
M.I.T. Press , 1971
Buku Teks