Syed Zain, Sharifah Fetom, Nazhatulshima Ahmad, and Mohd Zambri Zainuddin. “Helium λ 4009.27 Ã… Phase Variation in Alpha Virginis”. Malaysian Journal of Science 26, no. 2 (August 30, 2007): 143–149. Accessed December 22, 2024. https://juku.um.edu.my/index.php/MJS/article/view/8082.