Christova, I. ., Trifonova, I. ., Gladnishka, T. ., Dragusheva, E. ., Popov, G. . and Ivanova, V. . (2021) “Viral load and antibody levels in patients with COVID-19”, GSC Advanced Research and Reviews, 8(3), pp. 010–018. doi: 10.30574/gscarr.2021.8.3.0180.