Xiaowu Li Feng Pan Taixia Cheng Zhinan Wu Juan Liang Linke Hou Integrated Hybrid Second Order Algorithm for Orthogonal Projection onto a Planar Implicit Curve. 164 2018 10 Symmetry 5 https://doi.org/10.3390/sym10050164 https://www.wikidata.org/entity/Q129797415 db/journals/symmetry/symmetry10.html#LiPCWLH18