J. Sándor, L. I. Kovács
On perfect numbers connected with the composition of arithmetic function
Acta Universitatis Sapientiae, Mathematica, 1, 2 (2009) 183−192     Full text in PDF
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J. Sándor
A note on logarithmically completely monotonic ratios of certain mean values
Acta Universitatis Sapientiae, Mathematica, 2, 1 (2010) 84−91     Full text in PDF
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J. Sándor, R. Oláh-Gál
On Cusa-Huygens type trigonometric and hyperbolic inequalities
Acta Universitatis Sapientiae, Mathematica, 4, 2 (2012) 145−153     Full text in PDF
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