Shoimkulov Б. М., & Lukmon Р. М. С. (2021). Of one over determined system differential equations at private derivative second order with one singular lines in general case. BULLETIN OF PERM UNIVERSITY. MATHEMATICS. MECHANICS. COMPUTER SCIENCE, (2 (53), 10–15. https://doi.org/10.17072/1993-0550-2021-2-10-15