Maulana, Ahmat, Mahmud Yunus, and Dwi Sulistyaningrum. 2015. “The Constructions of Egg-Shaped Surface Equations Using Hugelschaffer’s Egg-Shaped Curve”. Indonesian Journal of Physics 26 (2), 26 - 30. https://doi.org/10.5614/itb.ijp.2015.26.2.2.