@article{DMGAA_2007_27_1_a4,
     author = {Dimitrova, Ilinka and Koppitz, J\"org},
     title = {Maximal submonoids of monoids of hypersubstitutions},
     journal = {Discussiones Mathematicae. General Algebra and Applications},
     pages = {69--85},
     publisher = {mathdoc},
     volume = {27},
     number = {1},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGAA_2007_27_1_a4/}
}