When you refer to someone’s work in your essay, you need to include an in-text citation. This is normally the surname(s) of the author(s) and the year their work was published. The citation normally comes at the end of a sentence in brackets:
Example: …although other authors have denied this (Hartley, 2019).
Or, if you include the author’s name as part of the sentence, put the year of publication immediately after in brackets:
Example: … Hartley (2019) declared that …
If you use a direct quote, include the page number.
Here is some example text showing what in-text citations look like: