Vadakalai Thenkalai

Vadakalais follow Vedanta Desikan giving Veda the first preference
http://sevenhillsinformation.blogspot.com/search/label/DivineBell

Books / Language
https://freeglobaluniversity.blogspot.com/search/label/Veda
https://freeglobaluniversity.blogspot.com/search/label/Sansk

whereas

Thenkalais follow Pillai Lokacharya giving Divya Prabandham the first preference
https://impartimpart.blogspot.com/search/label/SriPillaiLokacharya
Books / Language

https://freeglobaluniversity.blogspot.com/search/label/Veda

https://freeglobaluniversity.blogspot.com/search/label/Tamilakam

Google / Hagiographies / Article
https://www.google.com/search?q=Vadakalai+Thenkalai
https://en.wikipedia.org/wiki/Ramanuja#Hagiographies
https://www.bhagavadgitausa.com/vadakalai_tenkalai.htm