Rothkegel, R Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society; Max Planck Institute for Biological Cybernetics, Max Planck Society;
https://link.springer.com/content/pdf/10.1007/s004260000021.pdf (Publisher version)
Wender, K., & Rothkegel, R. (2000). Subitizing and its subprocesses. Psychological Research-Psychologische Forschung, 64(2), 81-92. doi:10.1007/s004260000021.