Varadarajan, V. S., « Review: Lie groups. An approach through invariants and representations, by Claudio Procesi », Bull. Amer. Math. Soc. (N.S.), vol. 45, no 4, , p. 661–674 (DOI10.1090/s0273-0979-08-01201-9, lire en ligne)
(en) Claudio Procesi et Murray Schacher, « A non-commutative real Nullstellensatz and Hilbert's 17th problem », Annals of Mathematics, 2e série, vol. 104, no 3, , p. 395-406 (DOI10.2307/1970962).
Varadarajan, V. S., « Review: Lie groups. An approach through invariants and representations, by Claudio Procesi », Bull. Amer. Math. Soc. (N.S.), vol. 45, no 4, , p. 661–674 (DOI10.1090/s0273-0979-08-01201-9, lire en ligne)