@article{10_4153_CJM_1986_002_x,
     author = {Almeida, Jorge},
     title = {Some {Order} {Properties} of the {Lattice} of {Varieties} of {Commutative} {Semigroups}},
     journal = {Canadian journal of mathematics},
     pages = {19--47},
     year = {1986},
     volume = {38},
     number = {1},
     doi = {10.4153/CJM-1986-002-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1986-002-x/}
}