Information, National Center for Biotechnology; Pike, U. S. National Library of Medicine 8600 Rockville; MD, Bethesda; Usa, 20894 (2009). "TABLE 3, WHO PANDEMIC PHASE DESCRIPTIONS AND MAIN ACTIONS BY PHASE". www.ncbi.nlm.nih.gov (dalam bahasa Inggris). Diarsipkan dari versi asli tanggal 2020-04-21. Diakses tanggal 2020-06-30.
Information, National Center for Biotechnology; Pike, U. S. National Library of Medicine 8600 Rockville; MD, Bethesda; Usa, 20894 (2009). "TABLE 3, WHO PANDEMIC PHASE DESCRIPTIONS AND MAIN ACTIONS BY PHASE". www.ncbi.nlm.nih.gov (dalam bahasa Inggris). Diarsipkan dari versi asli tanggal 2020-04-21. Diakses tanggal 2020-06-30.