Density, excess properties, electrical conductivity and viscosity of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + γ-butyrolactone binary mixtures VraneÅ¡, M.; Papović, S.; Tot, A.; Zec, N.; Gadžurić, S.; The Journal of Chemical Thermodynamics 2014, 76, 161-171