Yogavallī, T Krishnamacharya’s commentary on the Yoga Sūtra, looking at the text from his personal Vaiṣṇavite viewpoint of Viśiṣṭādvaita or qualified non-dualism (One of the three primary schools of Vedānta).
AG Mohan on Krishnamacharya’s approach to Śīrṣāsana.
Said by AG Mohan to be from Yoga Makaranda Part 2
Also downloadable as a PDF
Also a downloadable PDF based on the Yoga Makaranda on Āsana practice,
especially variations around Śīrṣāsana (described here as Viparīta Karaṇī Mudrā)