@article {29051,
	title = {Efficient use of Toeplitz matrices for least squares data fitting by nonnegative differences},
	journal = {HERMIS-$\mu\pi$ Intl. Journal},
	volume = {Vol. 6},
	year = {2006},
	pages = {135-153},
	author = {I. C. Demetriou and EA Lipitakis and E.E. Vassiliou}
}
