[1] P. Billingsley: Convergence of Рrobability Measures. Willey, New York 1968.

[2] H. Cramér H. Wold: Some theorems on distгibution function. J. London Math. Soc. II (1936), 290-295.

[3] J. P. R. Christensen: On some measures analogous to Haaг measuгe. Math. Scand. 26 (1970), 103-106. MR 0260979

[4] R. O. Davies: Can two different measures agree on balls?. (Good news and bad news). Mimeographed notes, 1972.

[5] R. O. Davies: Measures not approximable or not specifiable by means of balls. Mathematika 18 (1971), 157-160. MR 0310162 | Zbl 0229.28005

[6] T. Neubrunn: A note on quantum probability spaces. Proc. Ameг. Math. Soc. 25 (1970), 672-675. . MR 0259056 | Zbl 0208.43402

[7] F. H. Ruymgaart: A note on the concept of joint distributions of pairs of obseгvables. The Indian Јournal of Statistics, Ser. A, Vol. 45 (1983), 38-43. MR 0749352