The integral representation of vector measures on a completely regular space

We consider the vector space $C(X,E)$ of all bounded continuous functions from a completely regular space $X$ into a Banach space $E$. It is given a special locally convex topology $\xi$. We prove the analog of the Riesz–Markov theorem for the $\xi$-continuous linear operators which map $C(X,E)$ into a Banach space $F$.