@article{10_4064_cm_64_1_79_92,
     author = {W. Lampe and J. Sichler and V. Trnkov\'a},
     title = {Homomorphisms of unary algebras and of their expansions},
     journal = {Colloquium Mathematicum},
     pages = {79--92},
     publisher = {mathdoc},
     volume = {64},
     number = {1},
     year = {1993},
     doi = {10.4064/cm-64-1-79-92},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-64-1-79-92/}
}