Johnson, Norman L.. "A Note on Free Planar Extensions.." Mathematische Zeitschrift 119 (1971): 281-282. <http://eudml.org/doc/171499>.
@article{Johnson1971, author = {Johnson, Norman L.}, journal = {Mathematische Zeitschrift}, keywords = {foundations of geometry}, pages = {281-282}, title = {A Note on Free Planar Extensions.}, url = {http://eudml.org/doc/171499}, volume = {119}, year = {1971}, }
TY - JOUR AU - Johnson, Norman L. TI - A Note on Free Planar Extensions. JO - Mathematische Zeitschrift PY - 1971 VL - 119 SP - 281 EP - 282 KW - foundations of geometry UR - http://eudml.org/doc/171499 ER -