@article{CMJ_2005__55_2_a10,
     author = {Hager, Anthony W. and Kimber, Chawne M. and McGovern, Warren W.},
     title = {Unique $a$-closure for some $\ell$-groups of rational valued functions},
     journal = {Czechoslovak Mathematical Journal},
     pages = {409--421},
     publisher = {mathdoc},
     volume = {55},
     number = {2},
     year = {2005},
     mrnumber = {2137147},
     zbl = {1081.06020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2005__55_2_a10/}
}