A simple nonanalytic equation of state has been obtained.
Alexander V. Tatarenko 2011, 'Elementary cuspoid catastrophes as the models of phenomenological equations of state',AIP Advanceshttp://dx.doi.org/10.1063/1.3562541. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)