A textbook derived from the content of <i>The Open Logic Text</i>
<a rel="nofollow" class="external text" href="https://openlogicproject.org/people/">Richard Zach, et al.</a>
CC BY 4.0
<a rel="nofollow" class="external free" href="https://openlogicproject.org/">https://openlogicproject.org/</a>