中国科学院数学与系统科学研究院期刊网
AMS
Maps Preserving Numerical Radius or Cross Norms of Products of Self-adjoint Operators
Kan HE, Jin Chuan HOU, Xiu Ling ZHANG
Acta Mathematica Sinica . 2010, (6): 1071 -1086 .  DOI: 10.1007/s10114-010-9001-y