Laplace transform of noncentral chi-square distribution I'm interested in non central chi-square distribution. More specifically, i want to derive the laplace transform of noncentral chi-sqruae disribution or density function. 

Let me know whether it exists or relevent book and paper. 

Thanks in advance
If you mean the probability function for the chi-square distribution with $r$ degrees of freedom 
$$P_r(x)=\frac{x^{-1+r/2}e^{-x/2}}{2^{r/2}\Gamma(r/2)}$$
The Laplace transform is :
$$\int_0^\infty P_r(x)e^{-sx}dx = \frac{(s+1/2)^{-r/2}\Gamma(r/2)}{2^{r/2}\Gamma(r/2)}= (2s+1)^{-r/2}$$
It is mentioned in the following paper:
http://link.springer.com/article/10.1007/BF02595410