In APA style, italicize sources that stand alone. Such works include books, reports, and websites. However, don’t italicize works that are part of the main source. Examples of such sources are journal articles and book chapters.
If an author name isn’t available, you may include a book, report, or website title in the in-text citation. In such cases, again only italicize sources that stand alone.
In APA style, italicize sources. Do not underline them.