Karunakaran, Thirunalloor
Malayala Bhasha Parinamam Sidhanthagalum Vasthuthakalum - 1st Ed. - Thiruvananthapuram Prabhat 1997
Malayala Bhasha Parinamam Sidhanthagalum Vasthuthakalum - 1st Ed. - Thiruvananthapuram Prabhat 1997