Isobaric VLE data for the system of butan-1-ol + butyl ethanoate + 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide Tian, Z.; Cui, X.; Cai, J.; Zhang, Y.; Feng, T.; Peng, Y.; Xue, L.; Fluid Phase Equilibria 2013, 352, 75-79