1. G. Alexits, Problems in the Convergence of the Orthogonal Series (Pergamon Press, New York-London, 1961).
2. W. Ambrose, Duke. Math. Journal. 11, 589 (1944).
3. F. Boukhari and M. Weber, Almost sure convergence of sequences of randomly selected ℂd-actions, unpublished work (2000).
4. F. Boukhari and M. Weber, Illinois J. Math. 46, 1 (2002).
5. D. Burkholder, Trans. Am. Math. Soc. 104(1), 123 (1962).