Articles discussing Nagardhan
New Light on the Epoch of the Kalacuri Era
V. V. Mirashi · The Indian Historical Quarterly, 1949
“The two records—the Nagardhan plates of Nannarija and the Ellori plates of Dantidurga—show that the epoch of the Kalacuri era, at least in some parts of Maharashtra and Vidarbha, was A.D. 250-51”
On the Date of the Ellora Plates of Dantidurga