Robles, Gemma. “Extensions of the Basic Constructive Logic for Weak Consistency BKc1 Defined With a Falsity Constant”. Logic and Logical Philosophy 16, no. 4 (February 26, 2008): 311–322. Accessed July 4, 2025. https://apcz.umk.pl/LLP/article/view/LLP.2007.010.