IT WOULD BE FINE TO FIND "MAHAPURUSHA-NIRNAYA" BY SHREE YAMUNACHARYA, BUT THE GRANTHA IS CONSIDERED TO BE LOST. DR. V. VARADACHARI WRITES THE FOLLOWING IN HIS #"YAMUNACHARYA"# TREATISE:
"The 8th and the last work of Shree YamunAcharya is "MahaPurusha-Nirnaya". As this title indicates, this work contained the author’s sound reasonings for deciding and determining Vishnu as the Supreme Deity.
Vishnu is here referred to as MahaPurusha, meaning "The Great Purusa, Paramatma or Purusottama". This work is referred to by the author in his AgamaPramanya where he adduces evidences for proving Vishnu’s Supremacy over other gods.
In this context, he mentions the name of the work in which he had already given ample proofs for deciding Supremacy over gods in favour of Vishnu.
This work is, however, lost and is known from references in the Agamapramanya of the author and the Nyayasiddharyana of Vedanta Desika".
[publishers Prof. M. Rangacharya Memorial Trust, Madras], p. 61