Ron Paul alludes to this speech in his book End the Fed (pp. 51-52):
Mises, at the time, was elderly but sharp. His subject was socialism, and his lecture explained why socialism always fails due to the absence of a free market pricing structure for capital goods... The lecture was held in a modest-sized classroom, but the place was overflowing. Popularizing Austrian economics at the time was in its very early stages, but it was obvious even then that there was a starvation for truth in economics.
Presented at the University of Houston in 1972. [33:30]