Estimation of Activity Coefficients for the Pairs of the System 2-Ethoxyethanol + 2-Ethoxyethyl Acetate + 2-Butoxyethanol + 2-Butoxyethyl Acetate Cortinovis, G.F.; Salvagnini, W.M.; Tavares, D.T.; Taqueda, M.E.S.; Journal of Chemical & Engineering Data 2011, 56, 4157-4163