Preserve Oxford comma

Author: ben

book/01-introduction/sections/about-version-control.asc

@@ -30,7 +30,7 @@ RCS works by keeping patch sets (that is, the differences between files) in a sp
 (((version control,centralized)))
 The next major issue that people encounter is that they need to collaborate with developers on other systems.
 To deal with this problem, Centralized Version Control Systems (CVCSs) were developed.
-These systems, such as CVS, Subversion and Perforce, have a single server that contains all the versioned files, and a number of clients that check out files from that central place. (((CVS)))(((Subversion)))(((Perforce)))
+These systems (such as CVS, Subversion, and Perforce) have a single server that contains all the versioned files, and a number of clients that check out files from that central place. (((CVS)))(((Subversion)))(((Perforce)))
 For many years, this has been the standard for version control.
 
 .Centralized version control.