שמיכה ממוצע דיילת how does polio spread רדיפה לדמיין בעיקרון
Polio - Our World in Data
How Is Polio Transmitted And Spread? - Ciriaco,Angeles-1/2b2016s2
Polio - Wikipedia
Wiping Out Polio: How The U.S. Snuffed Out A Killer : Shots - Health News : NPR
Poliomyelitis (Poliovirus) - YouTube
Pak Fights Polio on Twitter: "Do you know how #polio virus spreads?Polio is a highly contagious disease that can spread easily from person 2 person. RT to spread the msg https://t.co/oP3bKjyHjl" /