Each time you quote a source directly, paraphrase an idea, or refer to something that another person said or wrote identify the original source by inserting the author’s last name and the date within the text of your paper. Each source you cite must also appear in the reference list at the end of your paper.
These arguments against standardized education (Duckworth, 1986) explore science as a process of discovery.
Aim to cite one or two prime sources for each key point for a paper. However, for a literature review the expectation is for a more comprehensive list of citations.
(American Psychological Association, 2010, p. 169)