Gopala - Tapani Upanishad (Commentary by Srila Visvanatha Cakravarti Thakura & Srila Baladeva Vidyabhusana) - part of Atharva Veda, is often quoted by Gaudiya acaryas since it is a sruti text which clearly praises Krsna and the path of bhakti as supreme. Its main subject is Krsna. It also explains the Krsna mantra in detail. Jiva, Prabhodananda, Visvanatha, and Baladeva have written commentaries on this Upanisad. This work includes the commentaries of both Visvanatha and Baladeva.