"Estimating mean scatterer spacing with the frequency-smoothed spectral autocorrelation function," T. Varghese, and K. D. Donohue, IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, Vol. 42, No. 3, pp. 451-463, May 1995. PostScript (.ps)
"Mean scatterer spacing estimates with spectral correlation," T. Varghese, and K. D. Donohue, Journal Acoustic Society America, Vol. 96, No. 6, pp. 3504-3515, December 1994. PostScript (.ps.Z)
"Characterization of tissue microstructure scatterer distribution with spectral correlation," T. Varghese, and K. D. Donohue, Ultrasound Imaging Vol-15, pp 238-254, 1993. PostScript (.ps.Z)
"Spectral correlation in ultrasonic pulse-echo signal processing," K.D. Donohue. J. M. Bressler, T. Varghese, and N. M. Bilgutay, IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, Vol-40, July 1993, pp 330-337. PostScript (.ps)
"Spectral redundancy in characterizing scatterer structure from ultrasound echoes," K. D. Donohue, T. Varghese, and N. M. Bilgutay, Review of progress in Quantitative Nondestructive Evaluation, Vol-13, 1994. PostScript (.ps)
"Spectral cross-correlation for tissue characterization," K. D. Donohue, and T. Varghese, 1992 IEEE Ultrasonics Symposium, pp 1049-1052. PostScript (.ps)