On the logical philosophy of assertive graphsChiffi, Daniele; Pietarinen, Ahti-VeikkoJournal of logic, language and information2020 / 21 p https://doi.org/10.1007/s10849-020-09315-6 Journal metrics at Scopus Article at Scopus Journal metrics at WOS Article at WOS Proof analysis of Peirce's alpha system of graphsMa, Minghui; Pietarinen, Ahti-VeikkoStudia logica2017 / p. 625-647 : ill https://doi.org/10.1007/s11225-016-9703-y