TY - JOUR AU - Jean Larson TI - Pinning for pairs of countable ordinals JO - Fundamenta Mathematicae PY - 1980 SP - 7 EP - 21 VL - 108 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.4064/fm-108-1-7-21/ DO - 10.4064/fm-108-1-7-21 LA - en ID - 10_4064_fm_108_1_7_21 ER -