@article{10_4064_cm_53_1_1_7,
     author = {J. P{\l}onka},
     title = {On lattices of varieties of universal algebras},
     journal = {Colloquium Mathematicum},
     pages = {1--7},
     year = {1987},
     volume = {53},
     number = {1},
     doi = {10.4064/cm-53-1-1-7},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-53-1-1-7/}
}