Şahin T, Yilmaz M. On singularities of the Galilean spherical darboux ruled surface of a space curve in $G_3$. Ukr. Mat. Zhurn. [Internet]. 2010Oct.25 [cited 2024Apr.20];62(10):1377–1387. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/2962