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)