1. D. Rothlein and B. Rapp, “The similarity structure of distributed neural responses reveals the multiple representations of letters,” NeuroImage, vol. 89, pp. 331–344, Nov. 2013, doi: https://doi.org/10.1016/j.neuroimage.2013.11.054.
2. S. P. D. Li, S.-P. Law, K.-Y. D. Lau, and B. Rapp, “Functional orthographic units in Chinese character reading: Are there abstract radical identities?”, Psychonomic Bulletin & Review, vol. 28, pp. 610–623, Nov. 2020, doi: https://doi.org/10.3758/s13423-020-01828-2.
3. Y. P. Chen, “What Are the Functional Orthographic Units in Chinese Word Recognition: The Stroke or the Stroke Pattern?”, Experimental Psychology, vol. 49, no. 4, pp. 1024–1043, Nov. 1996, doi: https://doi.org/10.1080/713755668.
4. S. Chen and I. Liu, “Functional Orthographic Units in Chinese Character Recognition”, Acta Psychology Sinica, vol. 32, pp. 13–20, Jan. 2000.
5. Meriam Webster, “radical”, entry 2, def. 1a, Incorporated, Meriam Webster, Incorporated.