Adding citations
To add a citation type \cite{} and then start entering the author’s name or reference number that’s be allocated to the source, into the citation and it will suggest which source you are referring to. As soon as you add a citation, the full reference list will automatically be added as you cite:
Mulitple citations
To cite multiple references together put a comma in the middle of your cite bracket and then you can add the second reference. So it would be \cite {reference, reference}. For example:
To add page numbers to your reference, after \cite you must type [p.~pagenumber] before the reference curly brackets so for example cite [p.~100]{Smith}.
Using Natbib to manage citations in Overleaf
Natbib is useful for managing references if you are using an author date style such as Harvard Bath. Near the top of your main text file enter \usepackage{natbib}
However, if you’re using Harvard Bath, you’ll need to edit your references so that they appear within brackets. You can do this by changing \cite to \citep{} and then enter the source in the curly brackets.
Omitting author's names
With using Natbib you can omit authors names, which in Harvard Bath style you would do where the author’s name from the citation where it naturally occurs in the text. To do this type \citeyearpar{} and then enter the source in the curly brackets.
Further guidance on Natbib
For further guidance on Natbib look at Overleaf's guidance.