Reference list:

Singh, J., Kour, K., & Jayaram, M. B. (2012). Acetylcholinesterase inhibitors for schizophrenia. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD007967.pub2

The citation in your text will be:

Singh et al. (2013) or (Singh et al., 2013)…

or, if you have quoted directly,

(Singh et al., 2013, p.23)

If you have used the author's name in your sentence then only the year of publication, with a page reference if necessary, is placed after it in brackets, eg.

Singh et al. (2013) suggest that ...

or, if you have quoted directly,

Singh et al. (2013, p.23) state that ...

Interested in systematic reviews?

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They explain the systematic review process and cover a variety of relevant topics include including formulating an appropriate review question, devising a search strategy, assessing the quality of studies found and analysing and synthesising data.