H. El-Sayed, Nabil, Nagwa M. Ammar, Sahar Y. Al-Okbi, Lamia T. Bou-El-Kassem, and Tom J. Mabry. 2010. “Phenolics and Lipid Antioxidants from Washingtonia Robusta”. Asian Journal of Chemistry 18 (4):2827-30. https://asianpubs.org/index.php/ajchem/article/view/20693.