American Academy of Arts and sciences, 1971
Buku Teks
Gooch, G.P., author
Beacon Press, 1968
Buku Teks
Pfitzer, Gregory M., author
Northeastern University Press, 1991
Buku Teks
Momigliano, A. D.
Weidenfeld and Nicolson, 1966
Buku Teks
Powicke, F. M.
Odhams Press, 1955
Buku Teks