I would enter each book as a separate title, and use Overall Title Name and Book # (both Title level fields) to 'link' the books together.
I also tend to add the Publisher to the Title as the same book could be published by different Publisher over time.
Also, in general, Magazine type issue numbering doesn't work well for books. For example if you used 200108 for the 1st printing, what would you use for 2nd (and up) printings? 200108-2, 200108-3 when the 2nd and 3rd printings were NOT printed the same year/month doesn't look good.
As an example:
Title Overall Title Name Book #
Retribution (Gold Eagle) Mack Bolan 1
Ambush (Gold Eagle) Mack Bolan 2
Stolen Arrows (Gold Eagle) Mack Bolan 3
NOTE: I am assuming a Publisher of 'Gold Eagle' as I found some issues on Ebay but without access to the book, it could be some other publisher.
Also, the Book # I listed are just an example as I don't know the publishing sequence.