@article{701195,
     title = {Birkhoff variety theorem for finite algebras},
     booktitle = {Abstracta. 8th Winter School on Abstract Analysis},
     series = {GDML\_Books},
     publisher = {Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1980},
     pages = {134-137},
     url = {http://dml.mathdoc.fr/item/701195}
}

Reiterman, Jan. Birkhoff variety theorem for finite algebras, dans Abstracta. 8th Winter School on Abstract Analysis, GDML_Books,  (1980), pp. 134-137. http://gdmltest.u-ga.fr/item/701195/