@article{ARM_1977__13_3_a1,
     author = {Chajda, Ivan},
     title = {Weak homomorphisms of systems of equations},
     journal = {Archivum mathematicum},
     pages = {135--140},
     publisher = {mathdoc},
     volume = {13},
     number = {3},
     year = {1977},
     mrnumber = {0460215},
     zbl = {0375.08004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1977__13_3_a1/}
}