Evaluation of Immune Boosting Properties and Combating of Multiple Respiratory Viral Infections by fifteen Euphorbiaceae Plant Extracts, Abd-Alla, Howaida I., Sweelam Heba-tollah M., El-Kashak Walaa A., and El-Safty Mounir M. , Pharmacognosy Journal, November 2019, Volume 11, Issue 6s, p.1490-1503, (2019)