Final answer:
In-text (parenthetical) citations use only the page number when the author's name is included in a signal phrase. If there are two authors, include both names in the citation. APA-style citations require only the publication year when the author is mentioned in the sentence. Unknown authorship requires using the title of the work.
Step-by-step explanation:
The format for an in-text (parenthetical) citation that includes the author's name in a signal phrase is straightforward: only the page number is needed in parentheses. For example, when narratively introducing a source with a signal phrase like 'According to John Smith', and then directly quoting or paraphrasing from the source, you would format it as follows:
'In discussing the narrative strategies used in his novels, Smith asserts that “themes of identity are central” (45).' Here, the parenthetical citation consists only of the page number from which the quoted or paraphrased material comes since the author's name is already provided in the signal phrase.
If the work being cited has two authors, such as Kristof and WuDunn, the parenthetical citation would include both names when a signal phrase is not used (Kristof and WuDunn, 14), or just the page number when a signal phrase is used. In APA-style in-text citations, when an author's name is cited in the sentence, only the year of publication is included in the parentheses.
Additionally, if the author of a work is unknown, the work's title is used in the signal phrase or a shortened version in the parentheses, with articles being placed in quotation marks and book or journal titles in italics.