Excess thermodynamic properties of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate and N-octyl-2-pyrrolidone from T = (298.15 to 323.15)K at atmospheric pressure Govardhana Rao, S.; Madhu Mohan, T.; Vijaya Krishna, T.; Raju, K.; Subba Rao, B.; The Journal of Chemical Thermodynamics 2015, 89, 286-295