@article{IM2_1968_2_1_a8,
     author = {V. A. Yankov},
     title = {On the extension of the intuitionist propositional calculus to the classical calculus, and the minimal calculus to the intuitionist calculus},
     journal = {Izvestiya. Mathematics },
     pages = {205--208},
     publisher = {mathdoc},
     volume = {2},
     number = {1},
     year = {1968},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1968_2_1_a8/}
}