@article{SF_1976__12_134154,
     author = {P. L. Brockett},
     title = {Admissible transformations of measures.},
     journal = {Semigroup forum},
     pages = {21--33},
     publisher = {mathdoc},
     volume = {12},
     year = {1976},
     zbl = {0322.60008},
     url = {http://geodesic.mathdoc.fr/item/SF_1976__12_134154/}
}