TY - JOUR AU - Sochor, AntonĂ­n TI - Addition of initial segments. I JO - Commentationes Mathematicae Universitatis Carolinae PY - 1988 SP - 501 EP - 517 VL - 29 IS - 3 UR - http://geodesic.mathdoc.fr/item/CMUC_1988_29_3_a10/ LA - en ID - CMUC_1988_29_3_a10 ER -