ThermoDex contains annotated bibliographic records describing print compilations of thermodynamic and physical property data for chemical compounds and other substances. Entering both a property and type of compound provides a list of handbooks that might contain these data. (UT Austin)
The "NIST Literature Report Builder for Thermophysical and Thermochemical Property Measurements" gives you the conditions for the measurement and the full literature reference, but NOT the actual property value.
Online access to books, databases, and conference proceedings from a number of publishers that cover all areas of engineering and includes content relevant to related sciences (e.g., chemistry and earth sciences). It includes interactive graphs and tables.