00575naa#a2200181#i#450# EN\NORMA\bibl\41774 20250109163529.4 1991-3222 20210112b2021####ek#y0engy0150####ca RU Regulation of Unforeseen Circumstances in the Relations of Obligations in German Law Journal article Moscow Legal publishing house Norm 2021 0 с. Journal article local Право. Юридические науки. 34 Aliev Azer Libik Rebekka zh-szf.ru