These intertwined circles aim to visualize the circulations of pharmaceutical brands between the Chinese and British newspapers Shenbao and North China Daily News (1914-1949). The red circle stands for the Chinese newspaper Shenbao: pharmaceutical brands and firms confined to this newspaper are inscribed in this red circle. The blue circle stands for the British newspaper North China Daily News. Shared brands stand at the intersection of the two circles.

These circles have been built after the related brandstrees (see the "Trees" section). These trees have proved useful tools to separate shared/specific brands, to precisely locate and periodize either circulations or blockades between both newspapers, to identify periods of maximal convergences/divergences.

Six circles of this kind have been drawn - one per sample, plus a synthetic circle showing "long-term" shared brands or advertisers.