  For $n$ independent random variables having the same H\"older continuous
density, this paper deals with controls of the Wolverton-Wagner's estimator MSE
and MISE. Then, for a bandwidth $h_n(\beta)$, estimators of $\beta$ are
obtained by a Goldenshluger-Lepski type method and a Lacour-Massart-Rivoirard
type method. Some numerical experiments are provided for this last method.
