1. Bibliotheca historica: Book II: The East. by Diodorus Siculus, 1st century BC, p. 35-60.
2. Sachau, Edward C. (1910). Alberuni's India — An account of ... India about A.D. 1030 (Vol. 1). Kegan Paul, Trench Trubner & Co.Ltd., London.
3. Hunter, William Wilson, Sir (1893). A Brief History of the Indian Peoples. Oxford: Clarendon Press.
4. Mookerji, Radhakumud (1912). Indian Shipping: A history of the sea-borne trade and maritime activity of the Indians from the earliest times. Longmans, Green and Co., Bombay.
5. The History and Culture of the Indian People, 11 vols, ed. R.C. Majumdar. (1951).
6. Indica by Megasthenes, c. 300 BCE
7. Bannerjee, Dr. Gauranganath (1921). India as known to the ancient world. Humphrey Milford, Oxford University Press, London.
8. History corner experts column com article important foreign travellers ancient india.