Quasiarithmetic-type invariant means on probability space

For a family $(\mathscr{A}_x)_{x \in (0,1)}$ of integral quasiarithmetic means sattisfying certain measurability-type assumptions we search for an integral mean $K$ such that $K\big((\mathscr{A}_x(\mathbb{P}))_{x \in (0,1)}\big)=K(\mathbb{P})$ for every compactly supported probabilistic Borel measure $\mathbb{P}$. Also some results concerning the uniqueness of invariant means will be given.