The New Relativity (ECE and ECE2 theories) are based directly on only three simple equations of standard Cartan geometry:
T = D ^ q
R = D ^ omega
D ^ T := R ^ q
These are explained more fully in Sean Carroll’s online book “Spacetime and Geometry: an Introduction to General Relativity”, chapter three. This chapter three is greatly developed in all detail in the UFT books and papers on www.aias.us and www.upitec.org. I think that Sean Carroll is now at Caltech. I know that he e mailed the late Prof. John B. Hart to say that ECE at the time was a plausible theory. All the papers and books of ECE and ECE2 are on Google Scholar, and all the books and papers of the Omnia Opera on www.aias.us. I have checked that the most recent papers are on Google Scholar. For example type in “Cartan Geometry and the Gyroscope” to Google Scholar as a random check. Google Scholar is cited by Wikipedia, so all the ECE and ECE2 papers are on Wikipedia.