Tim Button and P.D. Magnus, forallx:Cambridge - An Introduction to Formal Logic (Sep 22, 2018)

Tim Button, Metatheory (Sep 22, 2018)

Christopher S. Morrissey, forallx:–YXX+(Aristotelian+Term+Logic+edition) (Jan 7, 2020)

ISBN 978-7565135774 

Socratic Logic Advanced

Four Ages Perplexed Signs




Logic Textbooks: forallx-yyc and Open Logic Project