Feng Qi Pietro Cerone Sever Silvestru Dragomir H. M. Srivastava Alternative proofs for monotonic and logarithmically convex properties of one-parameter mean values. 129-133 2009 208 Applied Mathematics and Computation 1 http://dx.doi.org/10.1016/j.amc.2008.11.023 db/journals/amc/amc208.html#QiCDS09