Correlation between amniotic fluid optical density and L/S ratio.
Sbarra AJ, Michlewitz H, Selvaraj RJ, Mitchell GW, Cetrulo CL, Kelley EC, Kennedy JL, Herschel MJ, Paul BB, Louis F. Correlation between amniotic fluid optical density and L/S ratio. Obstet Gynecol. 1976 Nov; 48(5):613-5.