Q. How do I cite an source within a source?
That's a great question! What you are referring to is an indirect or secondary citation. It sort of depends on which format you are using as your citation style (APA, MLA?). If you are using APA, then the way to cite a source that is cited within another is to use the source you are reading in the Reference List, and refer to the one you want to use in the in-text reference, noting that it appears in another publication.
The following example is from the APA site (http://www.apastyle.org/learn/faqs/cite-another-source.aspx):
For example, if Allport's work is cited in Nicholson and you did not read Allport's work, list the Nicholson reference in the reference list. In the text, use the following citation:
Allport's diary (as cited in Nicholson, 2003).
So for your example, you would want to use Joe Smith's article in the References, but in the in-text citation, you would use the Jones article, with a notation (as cited in Smith, 2009) - I just made up the year here, but hopefully you get the idea.
If you are using a quote from another source, then you would say (as quoted in) instead of as cited in ... and you would need to provide the year and page number.
If you are doing MLA style, you would still use the source you have in front of you in the Works Cited, but you would use (qtd. in Smith 110) or whatever page it was from. You would use "qtd. in" even if it is a paraphrase and not a quote, because that is just how MLA distinguishes indirect material.
It should be noted that secondary sources should be used sparingly, and that it is usually best practice to locate the original source of the material if possible.