1. Square of Opposition: A Diagram and a Theory in Historical Perspective;Beziau, J.Y.
2. Ancient Formal Logic;Bocheński, J.M.
3. Two Squares of Opposition in Two Arabic Treatises: al-Suhrawardī and al-Sanūsī;Chatti, S.
4. The logic of △;Christensen, R.
5. On Certain Mathematical Terms in Aristotle’s Logic: Part II;Einarson, B.