NAJEEB, Nida; AHMAD, Khaleel; YAR, Sahib. A Hilfer Fractional Vaccination Epidemic Model: Stability Analysis and a Physics-Informed Neural Network Validated on COVID-19 Data. International Scientific Spectrum, [S. l.], p. 1–32, 2026. DOI: 10.66972/iscis21202621. Disponível em: https://iscis-journal.org/index.php/iscis/article/view/21. Acesso em: 13 oct. 2026.