On universal enveloping algebras and homology of loop spaces: Yves Félix, Stephen Halperin, Jean-Claude Thomas, Rational Homotopy Theory, Graduate Texts in Mathematics, 205, Springer-Verlag, 2000 (doi:10.1007/978-1-4613-0105-9) Yves Félix, Steve Halperin, Rational homotopy theory via Sullivan models: a survey, Notices of the International Congress of Chinese Mathematicians Volume 5 (2017) Number 2 (arXiv:1708.05245, doi:10.4310/ICCM.2017.v5.n2.a3) On rational homotopy theory of non-nilpotent...