中国科学院数学与系统科学研究院期刊网
AMS
Further Bounds for Hardy Type Differences
Kristina KRULIĆ, Josip PEČARIĆ, Dora POKAZ
Acta Mathematica Sinica . 2012, (6): 1091 -1102 .  DOI: 10.1007/s10114-012-0592-3