Vellanki Venkata Sundara Raghava Chetan Krishna, Busam Karthikeya, Santosh Yachareni, Saraswatula Sree Rama Krishna Chaithnya, Abhishek Srivastava: A Low-Supply, Sub-mW 1 GHz Ring Oscillator Achieving < 5% Frequency Variation Across PVT for Reliable On-Chip Clocking. VLSID 2026: 419-424