Mathisen, Trygve
Oslo University Press, 1959
Buku Teks
Wright, Quincy, author
Appleton-Century-Crofts, 1955
Buku Teks
Wright, Quincy, author
Appleton-Century-Crofts, 1955
Buku Teks
Linklater, Andrew, author
Cambridge University Press,, 2006
Buku Teks
Pigors, Paul, author
McGraw-Hill, 1961
Buku Teks