Refinement of an inequality of E. Landau. Alzer, H. — 1993 Acta Mathematica Universitatis Comenianae. New Series
Note on an inequality involving ( n ! ) 1 / n . Alzer, H. — 1995 Acta Mathematica Universitatis Comenianae. New Series
Errata to: Note on an inequality involving ( n ! ) 1 / n . Alzer, H. — 1996 Acta Mathematica Universitatis Comenianae. New Series