Influence of temperature and pressure on the density and speed of sound of 2-hydroxyethylammonium propionate ionic liquid Sarabando, J.A.; Magano, P.J.; Ferreira, A.G.; Santos, J.B.; Carvalho, P.J.; Mattedi, S.; Fonseca, I.M.; The Journal of Chemical Thermodynamics 2018, 122, 183-193