Ratna Sari, E. 2015. KESTABILAN GLOBAL BEBAS PENYAKITFLU SINGAPURA (Hand, Foot and Mouth Disease)BERDASARKAN MODEL SEIRS. PYTHAGORAS Jurnal Matematika dan Pendidikan Matematika. 7, 1 (Jan. 2015). DOI:https://doi.org/10.21831/pg.v7i1.2833.