TY  - JOUR
AU  - Ditor, Seymour
TI  - A New Kind of Free Extension for Projective Planes
JO  - Canadian mathematical bulletin
PY  - 1962
SP  - 167
EP  - 170
VL  - 5
IS  - 2
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1962-018-2/
DO  - 10.4153/CMB-1962-018-2
ID  - 10_4153_CMB_1962_018_2
ER  -