Mat Isa, Mansor, et al. “Reproductive Biology of the Sleeper Goby, Butis Gymnopomus (Bleeker, 1853) from the Merbok Estuary, Kedah, Malaysia”. Indian Journal of Fisheries, vol. 59, no. 4, Dec. 2012, https://epubs.icar.org.in/index.php/IJF/article/view/18180.