On the Cauchy--Rassias Inequality and Linear n-Inner Product Preserving   Mappings
  We prove the Cauchy-Rassias stability of linear n-inner product preserving mappings in $n$-inner product Banach spaces. We apply the Cauchy-Rassias inequality that plays an influencial role in the subject of functional equations. The inequality was introduced for the first time by Th.M.Rassias in his paper entitled: On the stability of the linear mapping in Banach spaces, Proc. Amer. Math.Soc. 72(1978), 297-300. 
Choonkil Baak, Hahng-Yun Chu and Mohammad Sal Moslehian