The Story of the Bobbsey Twins
- Comments include some history, some inconsistencies in the books, and dates of revisions.
- http://pw1.netcom.com/~drmike99/aboutbobbsey.html

About.com: Collecting The Bobbsey Twins Books
- Information about the first editions of The Bobbsey Twins books.
- http://collectbooks.about.com/cs/childrensbooks2/a/bobbseytwins.htm

Who Wrote the Bobbsey Twins?
- Tells who wrote various volumes in the series, who rewrote some of the earlier ones to update them, and gives dates of publication of the various titles. Includes some bookcovers and author photos.
- http://www.keeline.com/BobbseyWriters.html