ForewordPietarinen, Ahti-VeikkoLogic of the future : writings on existential graphs. Volume 1. History and applications2020 / p. XV-XVI https://www.degruyter.com/downloadpdf/book/9783110651409/10.1515/9783110651409-204.xml https://doi.org/10.1515/9783110651409-204

General Introduction to Logic of the FuturePietarinen, Ahti-VeikkoLogic of the future : writings on existential graphs. Volume 1. History and applications2020 / p. 1-13 https://doi.org/10.1515/9783110651409-001

Introduction to the Theory of Existential Graphs and Volume 1Pietarinen, Ahti-VeikkoLogic of the future : writings on existential graphs. Volume 1. History and applications2020 / p. 14-36 https://doi.org/10.1515/9783110651409-002