Hanson, A.H.
London Routledge & Kegan Paul 1959,
Buku Teks
Koontz, Harold
McGraw-Hill, 1956
Buku Teks
Swerdlow, Irving
Frederick A. Praeger, 1975
Buku Teks
Hansen, Alvin Harvey, 1887-1975
MacGraw-Hill , 1947
Buku Teks
Hansen, Bent
Harvard University Press , 1958
Buku Teks