@article{MS2_1990__66_1_167099,
     author = {J. Duncan and A.L.T. Paterson},
     title = {Amenability for discrete convolution semigroup algebras.},
     journal = {Mathematica Scandinavica},
     pages = {141--146},
     publisher = {mathdoc},
     volume = {66},
     number = {1},
     year = {1990},
     zbl = {0748.46027},
     url = {http://geodesic.mathdoc.fr/item/MS2_1990__66_1_167099/}
}