Densities, ultrasonic speeds, excess and partial molar properties of binary mixtures of 2-pyrrolidone with isomeric propanediols at temperatures from 303.15 K to 323.15 K Krishna, T.S.; Nain, A.K.; Narendra, K.; Chenthilnath, S.; Punyaseshudu, D.; The Journal of Chemical Thermodynamics 2017, 111, 129-141