Puchuri, Liliana. About the Stability Between a Foliation of Degree Two and the Pencil of Conics That Defines It. Pro Mathematica 31, no. 61 (diciembre 12, 2020): 33-52. Accedido diciembre 1, 2023. https://revistas.pucp.edu.pe/index.php/promathematica/article/view/23267.