@article{10_21136_CMJ_1973_101186,
     author = {Jambor, Pavel},
     title = {An orthogonal theory of a set-valued bifunctor},
     journal = {Czechoslovak Mathematical Journal},
     pages = {447--454},
     publisher = {mathdoc},
     volume = {23},
     number = {3},
     year = {1973},
     doi = {10.21136/CMJ.1973.101186},
     mrnumber = {0338123},
     zbl = {0271.18010},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/articles/10.21136/CMJ.1973.101186/}
}