Hoepfner, G., Medrado, R., & Fernando Ragognette, L. (2022). The Baouendi-Treves approximation theorem for Gevrey classes and applications. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE, 23(1), 315-338. https://doi.org/10.2422/2036-2145.201912_008