Erratum to 'Dynamic impact testing of cellular solids and lattice structures: Application of two-sided direct impact Hopkinson bar' International Journal of Impact Engineering 148 (2021) 103767. (May 2021) - Fíla, Tomáš; Koudelka, Petr; Falta, Jan; Zlámal, Petr; Rada, Václav; Adorna, Marcel; Bronder, Stefan; Jiroušek, Ondřej