. but China is ready to join the exclusive group behind the cited patents or scientific articles. Scholars have found that many patent citations do not even belong to the same technological class.31 Alternatively, scholars have tracked the international diffusion of technological knowledge by identifying the first appearance of a breakthrough invention and its international reuse. Recent their diffusion over time and space. These studies map technological knowledge diffusion using How can breakthrough technologies be mapped? Breakthrough technologies emerge through the novel recombination of existing technical knowledge. Following the idea that innovation stems from recombining existing knowledge components, scholars have mapped the diffusion