Kumar, Sudhir, R. Venugopalan, V.K. Rao, A.K. Nair, and R. Chithiraichelvan. 2012. “Requirement of Major Nutrients for Annatto (Bixa Orellana L.) Seed Yield and Bixin Content”. Indian Journal of Horticulture 69 (03):399-403. https://www.journal.iahs.org.in/index.php/ijh/article/view/2011.