21 references, page 1 of 3 1. S. T. Ali, J. P. Antoine, and J. P. Gazeau, “Continuous frames in Hilbert space”, Annals of Physics, vol. 222, no. 1, pp. 1-37, 1993.

2. W. B. Arveson, “Subalgebras of C∗-algebras,” Acta Mathematica, vol. 123, pp. 141- 224, 1969.

3. M. S. Asgari and A. Khosravi, “Frames and bases of subspaces in Hilbert spaces,” Journal of Mathematical Analysis and Applications, vol. 308, pp. 541-553, 2005.

4. R. Beukema, Positive Operator-Valued Measures and Phase-Space Representations, Proefschrift, Technische Universiteit Eindhoven, 2003.

5. P. G. Casazza and G. Kutyniok, “Frames of subspaces,” in Wavelets, Frames and Operator Theory, vol. 345, pp. 87-113, American Mathematical Society, 2004.

6. G. Chiribella, G. M. D'Ariano, and D. Schlingemann, “Barycentric decomposition of quantum measurements in finite dimensions,” Journal of Mathematical Physics, vol. 51, 2010.

7. O. Christensen, An Introduction to Frames and Riesz Bases, Birkh¨auser, 2003

8. I. Daubechies, A. Grossmann, and Y. Meyer, “Painless nonorthogonal expansions,” Journal of Mathematical Physics, vol. 27, pp. 1271-1283, 1986.

9. J. Dixmier, Von Neumann Algebras, North-Holland, 1981.

10. R. J. Duffin and A. C. Schaeffer, “A class of nonharmonic Fourier series,” Transactions of The American Mathematical Society, vol. 72, pp. 341-366, 1952.