中国科学院数学与系统科学研究院期刊网
The Intersection of Left (Right) Weyl Spectrum of 2×2 Upper Triangular Operator Matrices
Yuan LI(1), Xiu Hong SUN(2), H
Acta Mathematica Sinica, Chinese Series . 2005, (4): 653 -660 .  DOI: 10.12386/A2005sxxb0081