00553naa#a2200169#i#450# EN\NORMA\bibl\39997 20241127003241.3 1605-6590 20201021b2020####ek#y0engy0150####ca RU Essence of a Contract and Consequences of Their Disagreement by Contractors Journal article Moscow Legal publishing house Norm 2020 0 с. Journal article local Право. Юридические науки. 34 Gruzdev Vladislav Viktorovich naukaru.ru