The following publications are possibly variants of this publication: 
- Influence of parametric perturbations on Lyapunov exponents of discrete linear time-varying systemsEvgenij Barabanov, Adam Czornik, Michal Niezabitowski, Aliaksei Vaidzelevich. scl, 122:54-59, 2018.  [doi] 
- On the Lyapunov exponents of infinite-dimensional discrete time-varying linear systemAdam Czornik, Piotr Jurgas. saga 2016: 496-499 [doi] 
- On Lyapunov and Upper Bohl Exponents of Diagonal Discrete Linear Time-Varying SystemsAdam Czornik, Alexander Konyukh, Iryna Konyukh, Michal Niezabitowski, Justyna Orwat. tac, 64(12):5171-5174, 2019.  [doi] 
- Proportional Local Assignability of Lyapunov Spectrum of Linear Discrete Time-Varying SystemsArtur Babiarz, Irina Banshchikova, Adam Czornik, Evgenii Makarov, Michal Niezabitowski, Svetlana Popova. siamco, 57(2):1355-1377, 2019.  [doi] 
- On assignability of Lyapunov spectrum of discrete linear time-varying system with controlArtur Babiarz, Irina Banshchikova, Adam Czornik, Evgenil Makarov, Michal Niezabitowski, Svetlana Popova. saga 2016: 697-701 [doi] 
- On new estimates for Lyapunov exponents of discrete time varying linear systemsAdam Czornik, Aleksander Nawrat. automatica, 46(4):775-778, 2010.  [doi]