Y. S. AHLAWAT and P. RAMACHANDRAN, D.K. GHOSH, S. MATHUR, K. N. GUPTA,. “Viroid Infection of Citrus in Central India”. Indian Phytopathology, vol. 55, no. 3, Sept. 2002, pp. 290-3, https://epubs.icar.org.in/index.php/IPPJ/article/view/18731.