@article{BAG_1987__24_138359,
     author = {Jerzy Plonka},
     title = {Distributed families of varieties of algebras},
     journal = {Beitr\"age zur Algebra und Geometrie},
     pages = {75--82},
     year = {1987},
     volume = {24},
     zbl = {0611.08003},
     url = {http://geodesic.mathdoc.fr/item/BAG_1987__24_138359/}
}