Alexander, R. ., Johnson, A. ., Thorpe, J. ., Gevedon, T. ., & Testa, S. . (2003). Canonical nucleosides can be utilized by T4 DNA ligase as universal template bases at ligation junctions. Nucleic Acids Research, 31(12), 3208-16. https://doi.org/10.1093/nar/gkg415 (Original work published 2003)