@article{10_1017_S0017089500010016,
     author = {Basallote, Manuela and D{\'\i}az, Santiago},
     title = {Some strong forms of the local duality ofultraproducts},
     journal = {Glasgow mathematical journal},
     pages = {9--13},
     year = {2000},
     volume = {42},
     number = {1},
     doi = {10.1017/S0017089500010016},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500010016/}
}