Author: Swami, Geethananda
Publisher:Sivagiri Mutt, Varkala
Copyright:1954
Author: Swami, Dharmatheerthar ധര്മ്മതീര്ത്ഥര് സ്വാമി
Publisher:Swami Krishnanada, Peingottukara
Copyright:1947
Author: Nair, M. Gopalkrishnan
Publisher:Sahitya Akademi, New Delhi
Copyright:2003