@article{IM2_1968_2_5_a3,
     author = {V. A. Yankov},
     title = {The calculus of the weak {{\textquotedblleft}Law} of excluded middle{\textquotedblright}},
     journal = {Izvestiya. Mathematics},
     pages = {997--1004},
     year = {1968},
     volume = {2},
     number = {5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1968_2_5_a3/}
}