@article{10_1090_S0894_0347_1994_1249391_8,
     author = {Magidor, Menachem and Shelah, Saharon},
     title = {When does almost free imply free? {(For} groups, transversals, etc.)},
     journal = {Journal of the American Mathematical Society},
     pages = {769--830},
     publisher = {mathdoc},
     volume = {07},
     number = {4},
     year = {1994},
     doi = {10.1090/S0894-0347-1994-1249391-8},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-1994-1249391-8/}
}