Lewis Carroll's seven charts (and many others) [Online resource]Moktefi, AmiroucheHandbook of the 6th World Congress and School on Universal Logic2018 / p. 145 http://www.uni-log.org/pro2018/HANDBOOK-UNILOG2018.pdf

Logical consequence in the diagrammatic system of assertive graphs [Online resource]Chiffi, Daniele; Pietarinen, Ahti-VeikkoHandbook of the 6th World Congress and School on Universal Logic2018 / p. 262-263 http://www.uni-log.org/pro2018/HANDBOOK-UNILOG2018.pdf

To Peirce Hintikka's Thoughts [Online resource]Pietarinen, Ahti-VeikkoHandbook of the 6th World Congress and School on Universal Logic2018 / p. 152 http://www.uni-log.org/pro2018/HANDBOOK-UNILOG2018.pdf