The discussion focuses on the need for equations related to isothermal compressibility and volume expansivity specifically for refrigerants in both liquid and gaseous phases. Various online resources are suggested, including links to engineering tools and databases, although some require payment. It is recommended to explore public domain resources such as the International Critical Tables, JANAF, Perry's Chemical Engineers' Handbook, and other handbooks on cryogenics and HVAC for relevant data. Additionally, references to scientific literature databases like Sci. Cit, Chem. Abstracts, and Phys. Abstracts are provided for further research on refrigerant properties. The equation for the change in internal energy of gases is also mentioned, highlighting its relevance to the discussion.