00512naa#a2200169#i#450# EN\\bibl\40347 20240429183003.1 2542-1840 20201106b2020####ek#y0engy0150####ca RU Cancellation of Service Contract Journal article Kemerovo Kemerovo State University 2020 7 с. Journal article local Право. Юридические науки. 34 Kichigin Sergey Vladislavovich jcenter.kemsu.ru