@article{10_1017_S0017089500009162,
     author = {Petrich, Mario and Reilly, Norman R.},
     title = {The modularity of the lattice of varieties of completely regular semigroups and related representations},
     journal = {Glasgow mathematical journal},
     pages = {137--152},
     year = {1990},
     volume = {32},
     number = {2},
     doi = {10.1017/S0017089500009162},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500009162/}
}