Magnot, J.-P. “On a Class of Closed Cocycles for Algebras of Non-Formal, Possibly Unbounded, Pseudodifferential Operators”. Methods of Functional Analysis and Topology, vol. 28, no. 4, Dec. 2022, pp. 324-32, https://doi.org/https://doi.org/10.31392/MFAT-npu26_4.2022.04.