Eggermont, Pierre Herman Leonard
The chronology of the reign of Asoka Moriya : a comparison of the data of the Asoka inscriptions and the data of the tradition
E.J. Brill, 1956
 Buku Teks SO
Thapar, B.K.
Recent archaeological discoveries in India / B.K. Thapar
Unesco, 1985
 Buku Teks SO
Waugh, Evelyn, 1903-1966
Decline and fall
Everyman's Library, 1993
 Buku Teks SO
Goodman, Craufurd D.
Decline and Renewal
Institute of International Education, 1966
 Buku Teks SO
Spengler, Oswald
Decline of the west
George Allen and Unwin, 1956
 Buku Teks