Expression in Escherichia coli of chemically synthesized genes for human insulin - Goeddel,D.V.; Kleid,D.G.; Bolivar,R.; Heyneker,H.L.; Yansura,D.G.; Crea,R.; Hirose,T.; Kraszewski,A.; Itakura,K.; Riggs,A.D. (Proc Natl Acad Sci USA, 1979)