You need add citation information for each source into report.bib. For latex report example, the bib file happens to be report.bib too (set by \bibfilename{report.bib} command inside latex report example.tex). The first two entries in report.bib are the followings:
![](https://courses.ie.bilkent.edu.tr/ie477/wp-content/uploads/sites/2/hm_bbpui/1653/bafu08xu88gmocd5rv3m1i6dt808ftfn.png)
Whenever I want to cite those books inside latex report example.tex, I use \cite{xie2018r} and \cite{wickham2017r}. Note that how I used the identifiers xie2018r and wickham2017r of both resources on the first line of each @book{…} entry. Below is line 109 of latex report example.tex where I cited the books:
![](https://courses.ie.bilkent.edu.tr/ie477/wp-content/uploads/sites/2/hm_bbpui/1653/x245h6vmfdflo3ztudfe99do574r1asj.png)
Then the output looks like
![](https://courses.ie.bilkent.edu.tr/ie477/wp-content/uploads/sites/2/hm_bbpui/1653/g5nl8l71efdzavsugbs74kxtwj1dz2le.png)
![](https://courses.ie.bilkent.edu.tr/ie477/wp-content/uploads/sites/2/hm_bbpui/1653/q4o4csvx41h2ymkt6b4z8mc3ntnsvq0b.png)
- You can use \citep{} instead of \cite{} if you want citation automatically enclosed inside parantheses.
- See the same example report.bib for bib entries for articles, web pages, Ph D theses.