Sri vedAnta sAra of Bhagavad rAmanuja "sri vedAnta sAra" (an external link)
SRIMATI ANDAL's TIRUPPAVAI
Other acharyas's works
Sri ParAsara BhattAr's "ashtashloki"
Sri Pillai Lokacharya's "Mumukshupadi"
Isavasyopanishad with the commentary of Sri chinna jeeyar Swamiji.
SONGS & PRAYERS
MadhurAshtakam by Jaya Deva Goswami
Bhajagovindam by Sri Adi Sankara AchArya
Sri vEnkatESa suprabhAtam
Sri vishNu sahasra nAma
SrI vishNu sooktham
Other books (external links)