@article{AL_1970_9_3_a1,
     author = {S. L. Bloom and D. J. Brown and R. Suszko},
     title = {Some theorems on abstract logics},
     journal = {Algebra i logika},
     pages = {274--280},
     publisher = {mathdoc},
     volume = {9},
     number = {3},
     year = {1970},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AL_1970_9_3_a1/}
}