11.6. References 337
11.6. References
All the results in the first three sections come from [18] and [19]. Theorem
11.4.6 comes from [159], though our proof follows [29]. Theorem 11.4.8 is
due to Connes ([41]), though the proof presented here is due to Popa (see
[155]). Finally, the first part of Theorem 11.5.4 is due to Murray and von
Neumann ([128]).