All references to written work should be in present tense since it still speaks.
Never leave the reader with a question mark in his or her head about who is being cited.
Indicate who is the source and how it was obtained.
If the author's name is used in the lead-in then all that is left to show is a page number. Of course in interviews that are done by the writer no pages exist and, since that is clear from the lead-in, none are expected.
However, if there is a page number, it should be included at the end of the citation at the end of the sentence, and should look something like this: "Bah! Humbug!" (Scrooge 3).
Scrooge is the author and the direct quote used was taken from page three of his Anti Christmas article "Idiots with Stakes of Holly Through Their Hearts."
If Scrooge was only being paraphrased the scholar then
it would look something like this: Midwinter Solstice! Phooey! Fraudulent
Claims! (Scrooge 3).