@article{10_4064_fm_97_1_17_36,
     author = {Dov Gabbay},
     title = {Undecidability of intuitionistic theories formulated with the apartness relation},
     journal = {Fundamenta Mathematicae},
     pages = {17--36},
     publisher = {mathdoc},
     volume = {97},
     number = {1},
     year = {1977},
     doi = {10.4064/fm-97-1-17-36},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-97-1-17-36/}
}