How to find out what plugins a wp site uses?

I'm trying to find out what plugins a wordpress website is using and i cannot figure it how to do it.
I already looked through the source code and i only see 2 plugins through the code. The site is on wordpress but has a groupon look and purpose.

If anyone has a suggestion on how to do it please let me know

Some plugins can be identified by a footprint such as a link built into the page, or some thing the page says. Paid plugins may leave a footprint but will take research to figure it out.

right button "view source code" crtl F search "plugins"

Thanks for the responses but i already looked through the code and no footprints whatsoever, i also looked through the css code to see if there is anything there, but no result....