D. DINAKARAN and R. JEY ARAJAN, R. VELAZHAHAN, T. MARIMUTHU,. “A New Disease of Opuntia Elatior in Tamil Nadu”. Indian Phytopathology, vol. 45, no. 2, Jan. 2012, pp. 276-81, http://epubs.icar.org.in/index.php/IPPJ/article/view/21675.