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2. H. Kumano-Go, Pseudo-Differential Operators (MIT Press, Cambridge, 1982).
3. E. M. Stein, Harmonic Analysis: Real-Variable Methods, Orthogonality, and Oscillatory Integrals (Princeton Univ. Press, Princeton, 1993).
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5. L. Hörmander, “On the $$L^{2}$$ continuity of pseudo-differential operators,” Comm. Pure Appl. Math. 24 (4), 529–535 (1971).
https://doi.org/10.1002/cpa.3160240406