@article{10_4064_fm_79_3_209_212,
     author = {R. Solomon},
     title = {A type of {\ensuremath{\beta}N} with $\ensuremath{\aleph}_0$ relative types},
     journal = {Fundamenta Mathematicae},
     pages = {209--212},
     publisher = {mathdoc},
     volume = {79},
     number = {3},
     year = {1973},
     doi = {10.4064/fm-79-3-209-212},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-79-3-209-212/}
}