Premakumari, S., G. Geetha, and R. P. Devadas. “Availability of Calcium from Tree Lettuce (<i>Pisonia alba</I>) on School Children”. The Indian Journal of Nutrition and Dietetics, vol. 15, no. 3, Mar. 1978, pp. 67-71, https://informaticsjournals.co.in/index.php/ijnd/article/view/12114.