Source: Vrindavan Today of 2012-12-2
- http://ignca.nic.in/nl001702.htm – article on Mathura
- Excavations at Sonkh 2500 years of a town in Mathura District
Herbert Härtel – FOC.L /696271
- Occupation thought to have been from 8th century BCE to 19th century CE. Stratification largely based on coin evidence.
- Second temple thought to be sanctuary for Naga cult.
Source: Smithsonian Institute