English annotation by Vishnudut1926: The highlight of this edition is "Shree Rahasya-Traya-Sara" (3rd part of the edition) - OM VishnuPad Shree Vedanta Desika's masterpiece creation dwelling on all aspects of Vadakalai Siddhanta (that is the Siddhanta of Northern Branch of Shree Ramanuja-Sampradaya).
For those ones who had not studied "Shree Rahasya-Traya-Sara" I recommend to turn to M. R. RajaGopala Ayyangar extended edition at first, you can also find it in my E-Library - #"SRIMAD RAHASYATRAYASARA OF SRI VEDANTA DESHIKA", translated by M. R. RajaGopala Ayyangar, published by Agnihotram Ramanuja, 1946#
Besides, please don't forget about the editions/translations by Oppiliappan Koil Dr. V. SadaGopan - you can find the very ample collections of Shree Vedanta Desika's Granthas there - SADAGOPAN.ORG
The scan had been found on archive.org in 2 page-binding (this binding is very inconvenient in case you read from 10-inch tablet).
As usually I have made split in PDF-Xchange and transformed the scan into 1-page binding. The above links are for 1-page binding, still if you need 2-pages version, please refer to - https://archive.org/details/ThreeGreatEpicCreationsOfVedantaDesikaKrishnaswamiK.R.
This scan belongs to my E-Library on Cryptpad (E-Library, containing crucial and the most recommended Vaishnava-Granthas), you can visit here - #Cryptpad light E-Library#