Senthilkumar, P., S. Paulsamy, K. K. Vijayakumar, and K. Kalimuthu. “In Vitro Regeneration of the Medicinal Herb of Nilgiri Shola, Acmella Calva L. From Leaf Derived Callus”. Plant Tissue Culture and Biotechnology, vol. 17, no. 2, May 2009, pp. 109-14, doi:10.3329/ptcb.v17i2.2566.