Surface Tension Measurements of Difluoromethane (R-32) and the Binary Mixture Difluoromethane (R-32) + 1,1,1,2-Tetrafluoroethane (R-134a) from (253 to 333) K Duan, Y.Y.; Lin, H.; Wang, Z.W.; Journal of Chemical & Engineering Data 2003, 48, 1068-1072