@article{DAN_1977_237_3_a1,
     author = {Yu. I. Zhuravlev},
     title = {Extremal algorithms in an algebra over incorrect algorithms},
     journal = {Doklady Akademii Nauk},
     pages = {509--512},
     publisher = {mathdoc},
     volume = {237},
     number = {3},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_237_3_a1/}
}