@article{10_1017_S0017089500008703,
     author = {Dixon, P. G.},
     title = {Unbounded approximate identities in normed algebras},
     journal = {Glasgow mathematical journal},
     pages = {189--192},
     year = {1992},
     volume = {34},
     number = {2},
     doi = {10.1017/S0017089500008703},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500008703/}
}