TY - JOUR AU - Neumann, B. H. TI - Some Remarks on Semigroup Presentations: Corrigendum and Addendum JO - Canadian journal of mathematics PY - 1968 SP - 511 EP - 511 VL - 20 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1968-050-0/ DO - 10.4153/CJM-1968-050-0 ID - 10_4153_CJM_1968_050_0 ER -