Hussin, Azhar, Azman Abdul Ghani, Khaira Ismail, Rosmadi Fauzi, Dorall, Richard, and Gokilan, S. 2008. “The Geology and Geomorphology of Pulau Jarak, Pulau Sembilan and Pulau Perak”. Malaysian Journal of Science 27 (3):1-6. https://ajap.um.edu.my/index.php/MJS/article/view/8737.