Well, by resources what do you mean by that? Are you looking for content or is there another reason. Plus what type of source do you need this for, it will provide a better understand on what to search for.
On some websites, you can right click the page, and view source. If they are using an external plugin-it is customary that the web developer provide information about the author, where the plug-in came from and license information.
Im sure that if you do a search for jQuery Sliders, you should be able to find horizontal and vertical varieties. You can also try emailing the web developer, their contact information may be on the page somewhere and just ask.