Citing a Work that Cites a Personal Communication I'm interested in knowing if/how to properly cite a personal communication within a reference and if credit should be given to the primary source (the personal communication), the secondary source (the reference that cites the personal communication), or both.

Hypothetical example:  There is a textbook which has tabular data that I would like to reference.  The textbook cites the tabular data as being from a personal communication with another author.  I see this as a quandary since:

(1)  If I reference the textbook without the personal communication, I am not giving proper credit to the original author (even though they never published the data separately in its own right)

(2)  If I reference the personal communication, this would be incorrect and perhaps fraudulent as it was not between myself and the author, I am only a third party, and I would not be giving proper credit to the textbook authors, which is how the data was published.

(3) If I reference both, that is somewhat awkward as that would imply that I found the data from both sources independently, even though I only found it in one.

What is the proper way to reference this?
This is a very odd situation, and you may want to consider carefully whether to use the source, per Nate Eldredge's comment above.  If you do want to use it, however, I would recommend citing the textbook, but mentioning their original source in prose:


  blah blah context context, per the table in [citation of Textbook], as attributed to [their source].


This way you give the citation and appropriate credit, but do not assert you have personal communication of your own.