中国科学院数学与系统科学研究院期刊网
The Basis Property of Root Vector Systems of Unbounded Hamiltonian Operators via Quadratic Operator Pencils
Yan Fen QIAO, Guo Lin HOU, Alatancang
Acta Mathematica Sinica, Chinese Series . 2019, (4): 613 -632 .  DOI: 10.12386/A2019sxxb0057