中国科学院数学与系统科学研究院期刊网
THE IMBEDDING PROBLEM FOR SYSTEMS WITH AN INCOMPLETE,COMMUTATIVE ADDITION~1
KE-CHAN KUO
Acta Mathematica Sinica, Chinese Series . 1951, (1): 68 -87 .  DOI: 10.12386/A1951sxxb0004