Filipkovska, M.S. 2019. A block form of a singular pencil of operators and a method of obtaining it. Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics. 89, (May 2019), 33-58. DOI:https://doi.org/10.26565/2221-5646-2019-89-04.