Inhibition of HIV-1 and simian immunodeficiency virus (SIV) reverse transcriptases by the 5′-triphosphates of 3′-azido-2′,3′-dideoxyuridine (CS-87), 3′-azido-3′-deoxythymidine (AZT), and 3′-azido-2′,3′-dideoxy-5-ethyluridine (CS-85) : B. F. H. Eriksson, R. F. Schinazi, and C. K. Chu. Veterans Administration Med. Ctr., and Emory University School of Medicine, Dept. of Pediatrics, Atlanta, Ga., and University of Georgia, Athens, Ga.