@article{01215959, title = {Approximation of }, journal = {The New York Journal of Mathematics [electronic only]}, volume = {3A}, year = {1998}, pages = {75-82}, zbl = {0914.28013}, language = {en}, url = {http://dml.mathdoc.fr/item/01215959} }
Akcoglu, M.A.; Baxter, J.R.; Ha, D.M.; Jones, R.L. Approximation of . The New York Journal of Mathematics [electronic only], Tome 3A (1998) pp. 75-82. http://gdmltest.u-ga.fr/item/01215959/