evidence: Gu Yuying, Liu Dayong, 2021. Analysis of the causes of the formation of the migration wave in Heilongjiang region in the early period of the Republic of China. Historical Records of Heilongjiang, (4): 16–19, 33. (in Chinese) [...] Wang Wan Li Xing, 2018. The Heilongjiang River in the context of Sino-Russian relations: from the boundary of disputes to cooperation. Russian, East European & Central Asian Studies, (1): 69–94, 157. (in Chinese) [...] Heilongjiang River (Amur River in Russia) watershed