In the paper a necessary and sufficient condition for the existence of consistent estimates constructed on the basis of independent observations is given, boundedness of the estimated function not being assumed.
 S. Jílovec: On the existence of superconsistent estimates
. Trans. Fourth Prague Conf. on Information Theory, Statistical Decision Functions, Random Processes (Prague, 1965). Academia, Prague, 1967, 343 - 380. MR 0220384