Articles discussing Tugra
Trade Relations of India With Africa Upto 14th Century A. D.
Ravindranath Vaman Ramdas · Sambodhi, 1997
Naval Warfare in Ancient India
Prithwis Chandra Chakravarti · The Indian Historical Quarterly, 1930
The Trade of India (continued)
P. T. Srinivas Iyengar · The Indian Historical Quarterly, 1925
Aryans and the Sea: Evidence from the Rgveda