1. Encyclopedia of Mathematics and its Applications;F Borceux,1994
2. Gel’fand, I.M., Vilenkin, N.Y.: Generalized Functions: Applications of Harmonic Analysis, vol. 4. Academic Press, New York (1964). (Translated by Amiel Feinstein)
3. Ghez, P., Lima, R., Roberts, J.E.: $$\text{ W }^*$$-categories. Pac. J. Math. 120, 79–109 (1985)
4. Heunen, C., Karvonen, M.: Limits in dagger categories. Theory Appl. Categ. 34(18), 468–513 (2019).
arXiv:1803.06651
5. Kadison, R.V., Ringrose, J.R.: Fundamentals of the Theory of Operator Algebras, vol. 2. American Mathematical Society, Providence (1997)