1. European Center for Disease Prevention and Control (ECDC), “disease background of COVID-19” available from: www.ecdc.europa.eu/en/2019-ncov-background-disease
2. 1mg. Corona Ebook. Pdf available from: http://www.1mg.com/articles/coronavirus-all-your-questions-answered/
3. World Health Organization (WHO): “coronavirus” available from: www.who.int/health-topics/corona-virus
4. A preliminary studyof the transmission dynamics of the human immunodeficiency virus (HIV), the causative agent of AIDS;Anderson;IMA J Math Appl Med Biol,1986
5. Analysis of a model for the pathogenesis of AIDS;Nikolaos;Math Biosci,1997