 Grove (1988) proves an analogous representation theorem for a systems of spheres semantics that generalizes Lewis’ (1973) semantics for counterfactuals. See the relevant section of the entry on the  logic of belief revision  for an introduction to Grove's possible world semantics. Segerberg (1995) formulates the AGM approach in the framework of dynamic doxastic logic. Lindström &amp; Rabinowicz (1999) extend this to iterated belief revision. Of necessity, our presentation of belief revision theory has been rather compressed. For an excellent article-length introduction, see the entry on  logic of belief revision,  Huber (2013a), or Lin (2019). For a book-length treatment see Gärdenfors (1988), Hansson (1999), or Rott (2001). 