You're writing a paper on solar energy, and a lot of the articles you've found keep referring to this gigantic study the Department of Energy did in the 1970s. It looks really great – but it's 700 pages long, really technical, and only available on microfilm, and the paper's due Tuesday. The articles summarize what it says – can't you just put in a citation of the Department of Energy study without going to the trouble of hitting the library again?
If Smith quotes from the Department of Energy study, you can use the same quote, but clearly note in your citation that you have taken the quote from Smith's article (Department of Energy 1979, cited in Smith 1984, p. 37).