@article{10_4064_fm_73_3_235_247, author = {P. Knight}, title = {Algebraic equivalence of ordinal numbers}, journal = {Fundamenta Mathematicae}, pages = {235--247}, publisher = {mathdoc}, volume = {73}, number = {3}, year = {1971}, doi = {10.4064/fm-73-3-235-247}, language = {en}, url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-73-3-235-247/} }