Andrzej Indrzejczak. Cut-free Double Sequent Calculus for S5. Logic Journal of the IGPL, 6(3):505-516, 1998. [doi]
@article{Indrzejczak98, title = {Cut-free Double Sequent Calculus for S5}, author = {Andrzej Indrzejczak}, year = {1998}, url = {http://www3.oup.co.uk/igpl/Volume_06/Issue_03/#indrzejczak}, researchr = {https://researchr.org/publication/Indrzejczak98}, cites = {0}, citedby = {0}, journal = {Logic Journal of the IGPL}, volume = {6}, number = {3}, pages = {505-516}, }