Christou, Konstantinos P., Courtney Pollack, Jo Van Hoof, and Wim Van Dooren. “Natural Number Bias in Arithmetic Operations With Missing Numbers – A Reaction Time Study”. Journal of Numerical Cognition 6, no. 1 (June 15, 2020): Article e5883. Accessed May 10, 2026. https://jnc.psychopen.eu/index.php/jnc/article/view/5883.