Density, speed of sound, viscosity and refractive index properties of aqueous solutions of vitamins B1.HCl and B6.HCl at temperatures (278.15, 288.15, and 298.15)K Dhondge, S.S.; Deshmukh, D.W.; Paliwal, L.J.; The Journal of Chemical Thermodynamics 2013, 58, 149-157