Note On Certain Inequalities for Neuman Means
  In this paper, we give the explicit formulas for the Neuman means $N_{AH}$, $N_{HA}$, $N_{AC}$ and $N_{CA}$, and present the best possible upper and lower bounds for theses means in terms of the combinations of harmonic mean $H$, arithmetic mean $A$ and contraharmonic mean $C$. 
Zai-Yin He, Yu-Ming Chu, Ying-Qing Song and Xiao-Jing Tao
math.CA