The second moment of Maass form symmetric square L-functions at the central point

Recently R. Khan and M. Young proved a mean Lindel\"of estimate on the second moment of central values of Maass form symmetric-square L-function on the interval T<|tⱼ|<T+T^1/5+, where tⱼ is a spectral parameter of the Maass form. We provide another proof of this result.