@article {213050,
	title = {Discrete and continuum models of COVID-19 virus, formal solutions, stability and comparison with real data},
	journal = {Mathematics and Computers in Simulation},
	volume = {190},
	year = {2021},
	pages = {222-230},
	author = {Hamdy I. Abdel-Gawad and Ahmed H. Abdel-gawad}
}
