聯俄容共
Kitamura's book "Daiichiji Kokkyōgassaku no Kenkyū: Gendai Chūgoku wo Keisei Shita Nidai Seiryoku no Shutsugen" ("Research on the First United Front: The Emergence of the Two Great Powers that Constitute Modern China") was published by Iwanami Shoten in 1998. He explains in detail the trends of the Chinese Nationalist Party and the Chinese Communist Party that have moved modern China, centering on the establishment, development, and collapse of the cooperative relationship which they forged over the course of the Nationalist Party's unification of China which was tentatively completed in 1928.