This information about Isaac Rucker (1780-1850) appears in a book. Apparently it was a book that someone at Ancestry.com digitized and indexed. It may have been a wonderful leather-bound book. It may have been a spiral bound photocopy of typewritten pages. There is just one question.
Based on the results at Ancestry.com it is anyone’s guess. The “Source information” does not say and the “Source information” itself is not very specific as Ancestry.com only includes a vague description for “North America, Family Histories, 1500-2000:”
Ancestry.com. North America, Family Histories, 1500-2000 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2016.
This database does include images of actual books, most notably the DAR lineage books. Those books do have some actual practical uses for some genealogists (with limitations).
But this reference to Isaac Rucker?
If this had been information I had never located in any other place and if this Isaac had been a brick wall, I would have considered using this information as clues to try and find the actual book (full text searches at (http://books.google.com), (http://www.archive.org), and (http://www.hathitrust.org) would have been good places to start.
The theoretical genealogist in me wonders how to cite this database entry. The practical genealogist in me tells me not to bother because I’m not putting something like this in my database anyway.
I don’t cite things I don’t use and I diligently avoid using things that appear to have been dropped from outer space into a database.
This reference above is equivalent to saying “here’s something I found in a book. Just don’t ask me what book.”