Next, gather all necessary information about the source Instead, determine what kind of source and PDF is and cite it in this print Citing PDF files is the same as how you cite a print publication, but with the inclusion of the URL or DOI. You will see what I mean when we discuss the APA PDF citation format in Use the author–date citation system to cite references in the text in APA Style. ,  ·Identifying the source to cite: The first step in citing a PDF in APA style is to identify the source.