-References contributed by Han-Wen Nienhuys, Miguel Filgueiras, Mark
-Basinski, Dorothea Blostein, Stephen Page, Jan Nieuwenhuizen.
+References and comments contributed by Han-Wen Nienhuys (HWN), Miguel
+Filgueiras, Mark Basinski (MB), Dorothea Blostein, Stephen Page (SP),
+Jan Nieuwenhuizen.