Hörmander, Lars; Melin, Anders Free systems of vector fields. (English) Zbl 0383.35013 Ark. Mat. 16, 83-88 (1978). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 12 Documents MSC: 35H10 Hypoelliptic equations PDF BibTeX XML Cite \textit{L. Hörmander} and \textit{A. Melin}, Ark. Mat. 16, 83--88 (1978; Zbl 0383.35013) Full Text: DOI OpenURL References: [1] Rothschild, L. P. andStein, E. M., Hypoelliptic differential operators and nilpotent groups.Acta Math. 137 (1976), 247–320. · Zbl 0346.35030 [2] Witt, E., Treue Darstellung Liescher Ringe.J. Reine Angew. Math. 177 (1937), 152–160. · JFM 63.0089.02 This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.