Quantitative non-destructive evaluation of porous composite materials based on ultrasonic wave propagation : semiannual progress report, March 15, 1987 - September 14, 1987
St. Louis, Mo. : Washington University, Dept. of Physics, Laboratory for Ultrasonics ; Hampton, Va. : NASA Langley Research Center ; [Springfield, Va. :] : [National Technical Information Service, distributor], [1987]