Explanation I use in comments on student papers:
A citation in footnote or endnote needs to have enough specific information to allow the reader to identify not just the source but also what in the source is relevant. If a footnote number after a phrase like “imitation of life” refers the reader to an anthology of collected essays, for instance, the actual note should identify the particular source in that anthology that you are citing (e.g., Sir Phillip Sidney, “An Apology for Poetry”). If the source being cited is large or complex, the note should also indicate what in particular you are referring to (unless your discussion makes this clear): for example, “See, for example, Sidney’s or Shelley’s application of the ‘imitation of life’ princple in the context of the ultimate aims of poetry.”
