中国科学院数学与系统科学研究院期刊网
A GENERALIZATION OF A FORMULA OF LANDSBERG AND A FURTHER GENERALIZATION OF AN INEQUALITY OF BUNIAKOWSKY
张世勋
Acta Mathematica Sinica, Chinese Series . 1957, (2): 229 -234 .  DOI: 10.12386/A1957sxxb0015