The above article was written with much research done through many volumes of South Indian Tamil Inscriptions (South Indian Tamil Inscription Series), Kerala Tamil Inscriptions (Travancore Archaelogical Series), Tamil Meikeerthi's of Chola kings, Tamil Historical poetic compositions such as Raja Raja Cholan Ula, Kulothunga Cholan Ula, Vikrama Cholan Ula, Sangara Cholan Ula, Kalingaththuparani, Kulasekara Alvar's Tamil Vaishnava compositions from Naalayira Thivya Pirapandam, Cheraman Perumal Nayanar's Tamil Saiva composition from the 11th Thirumurai, Periyapuranam of Seikkilar (12th Thirumurai) - a Tamil poetic treatise on the history 63 Tamil Saiva Saints of Tamil Nadu.

Also Elamkulam Kunjan Pillai's work titled "History of Kerala" in English too have been useful.