1. Aerts, D. (1981). The one and the many, towards a unification of the quantum and the classical description of one and many physical entities. PhD-thesis, Free University of Brussels.
2. Aerts, D. (1983). The description of one and many physical systems. In C. Gruber, C. Piron, T. M. TL’m, R. Weill (Eds.), Les fondements de la mŐcanique quantique, 25e cours de perfectionnement de l’Association Vaudoise des Chercheurs en Physique Montana, du 6 au 12 mars 1983 (pp. 63–148). Lausanne: l’A.V.C.P.
3. Amira H. B., Stubbe I. (1998) How quantales emerge by introducing induction within the operational approach. Helvetica Physica Acta 71: 554–572
4. Balbiani, P. (2007) Propositional Dynamic Logic. Online entry of the Stanford Encyclopedia of Philosophy
5. Baltag A., Smets S. (2005) Complete axiomatizations for quantum actions. International Journal of Theoretical Physics 44(12): 2267–2282