@article{MMNP_2020_15_a4,
     author = {Marek Kocha\'nczyk and Frederic Grabowski and Tomasz Lipniacki},
     title = {Dynamics of {COVID-19} pandemic at constant and time-dependent contact rates},
     journal = {Mathematical modelling of natural phenomena},
     eid = {28},
     publisher = {mathdoc},
     volume = {15},
     year = {2020},
     doi = {10.1051/mmnp/2020011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.1051/mmnp/2020011/}
}