Kerr 1940 - Contributions to the Flora of Siam (Thailand). Additamentum LIII (1940) Contributions to the Flora of Siam (Thailand). Additamentum LIII. Bulletin of Miscellaneous Information (Royal Gardens, Kew) 1940(5): 180. doi: 10.2307/4111567.
There is no corrections for Swertia calcicola yet.