He is usually dated to about the 12th (or 13th) century, and is generally credited with founding the "New Logic" (Navya Nyāya).
Toshihiro Wada, Gaṅgeśa and Mathurānātha on Siṃhavyāghralakṣaṇa of vyāpti [4], Saṃbhāṣā, Nagoya Studies in Indian Culture and Buddhism, vol. 19 (1997?), pp. 1-22.
Mrinalkanti Gangopadhyay, Gaṅgeśa on the Means for the Ascertainment of Invariable Concomitance, Journal of Indian Philosophy, vol. 3 (1975), pp. 167-208.
Bibliography:
Prāmāṇyajñaptivāda.
Jitendranath Mohanty, ed., Gangeśa's Theory of Truth, Centre of Advanced Study in Philosophy (Calcutta 1966).
Tattvacintāmaṇi.
Erich Frauwallner, Die Lehre von der zusätzlichen Bestimmung (Upādhiḥ) in Gaṅgeśas Tattvacintāmaṇiḥ, Sitzungsberichte der phil.-hist. Klasse Band 266.2 (Vienna 1970).
Stephen H. Phillips, From Gaṅgeśa's Tattvacintāmaṇi: Discourse on Perceptual Presentation of Something as Other than What It Is, Journal of Indian Philosophy, vol. 28 (2000), pp. 567-650.
Stephen H. Phillips & Chakrabarti Arindam, Epistemology of Perception: Gaṅgeśa's Tattvacintāmaṇi, Jewel of Reflection on the Truth / about Epistemology, the Perception Chapter, American Institute of Buddhist Studies (New York 2004).