Speeds of sound in {(1−x)CH4 + xN2} with x = (0.10001, 0.19999, and 0.5422) at temperatures between 170 K and 400 K and pressures up to 30 MPa Estela-Uribe, J.; Trusler, J.; Chamorro, C.; Segovia, J.; Martín, M.; Villamañán, M.; The Journal of Chemical Thermodynamics 2006, 38, 929-937