Place the last name and date, separated by a comma, within parentheses. A parenthetical citation can appear within or at the end of a sentence.

When modeling an informing system, we normally define one or more clients, one or more informers, and one or more channels through which informing takes place (Gill, 2015).

In this paper, we conduct a descriptive analysis of characteristics of TDKPTs from a systems perspective (Cilliers, 1998) as an approach to the study of TDKPTs.

If other text appears with the parenthetical citation, use commas around the year.

(see Gill, 2015, for more detail)

(The work by Cilliers, 1998, is a good example.)

When text and a citation appear together in parentheses, use a semicolon to separate the citation from the text; do not use parentheses within parentheses.

(for example, mobile phones; Gill, 2015)