1. Avron, A.: The method of hypersequents in the proof theory of propositional non-classical logics. In: Hodges, W., Hyland, M., Steinhorn, C., Truss, J. (eds.) Logic: from foundations to applications. Proc. Logic Colloquium, Keele, UK, 1993, pp. 1–32. Oxford University Press, New York (1996)
2. Belnap Jr., N.D.: Display logic. Journal of Philosophical Logic 11, 375–417 (1982)
3. Brünnler, K.: Deep sequent systems for modal logic. In: Governatori, G., Hodkinson, I., Venema, Y. (eds.) Advances in Modal Logic, vol. 6, pp. 107–119. College Publications (2006)
4. Brünnler, K.: Deep sequent systems for modal logic. In: Archive for Mathematical Logic (to appear, 2008) http://www.iam.unibe.ch/~kai/Papers/dsm.pdf
5. Lecture Notes in Computer Science;K. Brünnler,2001