S. Hofmann, Thin Solid Films, pp.398-399, 2001.

A. T. Wu, Investigation of oxide layer structure on niobium surface using a secondary ion mass spectrometry, Physica C: Superconductivity, vol.441, issue.1-2, p.79, 2006.
DOI : 10.1016/j.physc.2006.03.125

D. Donoho, De-noising by soft-thresholding, IEEE Transactions on Information Theory, vol.41, issue.3, p.613, 1995.
DOI : 10.1109/18.382009

J. Gauvain and C. Lee, Maximum a posteriori estimation for multivariate Gaussian mixture observations of Markov chains, IEEE Transactions on Speech and Audio Processing, vol.2, issue.2, p.291, 1994.
DOI : 10.1109/89.279278