1. Prawitz, D. (2006). Natural deduction. A proof theoretical study. New York: Dover Publications.
2. Prawitz, D. (2018). The fundamental problem of general proof theory. Studia Logica, 107, 11–29.
3. Prawitz, D. (2022a). The validity of inference and argument, forthcoming.
4. Prawitz, D. (2022b). Validity of inferences, forthcoming.
5. Prawitz, D. (2022c). Validity of inferences reconsidered, forthcoming.