From what I know, sample variance is 1/(n-1) summation (i = 1 to n) for (Xi - Xbar)^2

I have proven the expectation of the sample variance to be sigma.

Is there such thing as the variance of the sample variance?

Unlike finding the expectation, I'm stuck halfway while finding its variance as I can't evaluate Var[(Xi^2)] and Var[(Xbar)^2]. (Was able to evaluate E[(Xi^2)] and E[(Xbar)^2] when I expanded the sample variance when finding its expectation.)

Any hints?