Boruah, Bitupan, Amit Kumar, and Abhijit Das. “Cirsium Wallichii DC. (Asteraceae): A Key Nectar Source of Butterflies”. Journal of Threatened Taxa 12, no. 14 (October 26, 2020): 17049–17056. Accessed January 23, 2022. https://threatenedtaxa.org/index.php/JoTT/article/view/6008.