Include an in-text citation when you refer to, summarize, paraphrase, or quote from another source. For every in-text citation in your paper, there must be a corresponding entry in your reference list.
source: https://guides.libraries.psu.edu/apaquickguide/intext
A reference list is a list of all the sources you actually referred to in your work.
Your reference list should appear at the end of your paper. It provides the information necessary for a reader to locate and retrieve any source you cite in the body of the paper. Each source you cite in the paper must appear in your reference list; likewise, each entry in the reference list must be cited in your text.
Your references should begin on a new page separate from the text of the essay.
A bibliography is a list of all the sources you consulted for background reading. Bibliography is an optional, and can be requested by your school, department or professor to be included to the reference list.
Citations consist of standard elements, and contain all the information necessary to identify and track down publications, including: