中国科学院数学与系统科学研究院期刊网
JCM
On Self-adjointness of the Product of Two Second-order Differential Operators
Zhi Jiang CAO(1),Jiong SUN(2),
Acta Mathematica Sinica, Chinese Series . 1999, (4):  .  DOI: 10.12386/A1999sxxb0097