@article{BSL_2020_49_4_a2,
     author = {Niki, Satoru},
     title = {Empirical {Negation,} {Co-Negation} and the {Contraposition} {Rule} {II:} {Proof-Theoretical} {Investigations}},
     journal = {Bulletin of the Section of Logic},
     pages = {359--375},
     publisher = {mathdoc},
     volume = {49},
     number = {4},
     year = {2020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BSL_2020_49_4_a2/}
}