Blali, A., et al. “A Note on Pencil of Bounded Linear Operators on Non-Archimedean Banach Spaces”. Methods of Functional Analysis and Topology, vol. 28, no. 2, June 2022, pp. 105-9, https://doi.org/https://doi.org/10.31392/MFAT-npu26_2.2022.02.