@article{10_4064_cm_77_1_41_58,
     author = {V. Koubek and J. Sichler},
     title = {Equimorphy in varieties of double {Heyting} algebras},
     journal = {Colloquium Mathematicum},
     pages = {41--58},
     publisher = {mathdoc},
     volume = {77},
     number = {1},
     year = {1998},
     doi = {10.4064/cm-77-1-41-58},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-77-1-41-58/}
}