Open Mendeley Desktop and select the files you wish to export.
Go to the File menu and select Export. Save as BibTeX type and save to the same folder that contains your LaTeX files.
To create your bibliography in your LaTeX file, enter two commands:
\bibliography{yourfilename} where yourfilename refers to the name of the .bib file you exported from Mendeley. This command generates the bibliography.
To insert an in-text citation, enter this command:
\cite{__} where __ is the citation key assigned (in the .bib file) to the source you want to cite.