1. To find a perfect journal for your articles, see ElsevierJournalFinder
2. Encyclopedia Mathematics: https://www.encyclopediaofmath.org/index.php/Main_Page
3. Questions and Answers in Mathematics: https://math.stackexchange.com/
4. A Maple package for fast computing rational first integrals and Darboux polynomials of planar polynomial vector fields: see paper, arxiv, Maple package