Reversed Geometric Programs Treated by Harmonic Means R. DuffinElmor Peterson Indiana University Mathematics Journal 1973 text pdf 10.1512/iumj.1973.22.22045 10.1512/iumj.1973.22.22045 en Indiana Univ. Math. J. 22 (1973) 531 - 550 state-of-the-art mathematics http://iumj.org/access/