Page numbers are included in the in-text reference if you have used a direct quote or you want to direct the reader to a specific page or pages. When you are including a page number, a comma is used after the date.
For a single page use the abbreviation p.
And for multiple pages use the abbreviation pp.
For material without page numbers, give the paragraph number.
Example:
Some have argued (Gorringe 2011, p. 33) that "the fish swam against the current".
In their summary, Gilbert and Gilbert (2010) point out "animals have direct family relationships" (pp. 10-12).
"The study has shown how the results compared" (Smith 2012, para. 6).