Primary paper, Chemistry & Biology 1(4), pp. 223–229, December 1994; DOI 10.1016/1074-5521(94)90014-0. Publisher byline verifies Ronald R. Breaker and Gerald F. Joyce. Abstract Results reports selection from a randomized DNA population, lead-dependent cleavage, five selection rounds and an intermolecular catalyst with turnover rate about one per minute. Publisher record: www.sciencedirect.com/science/article/pii/1074552194900140 . The PubMed record contains an anomalous separate collective-author entry; it is not treated as an additional verified author.
Primary research: Journal of the American Chemical Society 121(23), pp. 5364–5372, 1999; published online 25 May 1999. The publisher abstract identifies both authors and the chimeric DNA/RNA substrates used to measure hydroxide-dependent phosphodiester cleavage. Abstract and p. 5364 explain internal phosphoester transfer involving the adjacent 2′-hydroxyl group.