1. van den Ban, E., Crainic, M.: Analysis on Manifolds. University of Utrecht, Lecture Notes (2009)
2. Bezyaev, V.I.: The essential adjointness of hypoelliptic operators in Sobolev spaces. Moscow Univ. Math. Bull. 32(4), 1–5 (1977)
3. Boggiatto, P., Rodino, L.: Quantization and pseudo-differential operators. Cubo Mat. Educ. 5(1), 237–272 (2003)
4. Botchway, L.N.A., Gaël Kibiti, P., Ruzhansky, M.: Difference equations and pseudo-differential operators on $$\mathbb{Z}^n$$. J. Funct. Anal. 278(11), 108473, 41 pp (2020)
5. Cardona, D., del Corral, C., Kumar, V.: Dixmier traces for discrete pseudo-differential operators. J. Pseudo-Differ. Oper. Appl. 11(2), 647–656 (2020)