@article{Gańczak:2021,
author
=
"M.Gańczak and O.Pasek and Ł.Duda-Duma and D.Świstara and M.Korzeń",
title
=
"Use of masks in public places in Poland during SARS-Cov-2 epidemic: a covert observational study",
journal
=
"BMC Public Health",
volume
=
"Vol. 21",
pages
=
"1--10",
year
=
"2021",
}