Chopra, Vivek S, Joung-Woo Hong, and Michael Levine. (2009) 2009. “Regulation of Hox Gene Activity by Transcriptional Elongation in Drosophila.”. Curr Biol 19 (8): 688-93. Reference Link
Shaevitz, Joshua W, Elio A Abbondanzieri, Robert Landick, and Steven M Block. (2003) 2003. “Backtracking by Single RNA Polymerase Molecules Observed at Near-Base-Pair Resolution.”. Nature 426 (6967): 684-7. Reference Link