How to put website links in "Used literature" slide of the presentation?
No. Websites change. You should include information such as time, date, version, etc. 

For Wikipedia in particular, you can read this: https://en.wikipedia.org/wiki/Wikipedia:Citing_Wikipedia#Examples_of_how_to_cite_Wikipedia

For general websites, similar ideas apply. Remember to appropiately cite dates, author names, and possibly also titles for the website content (e.g., if it's a blog article, the blog title should be included). Never just post a link, that's horrible style.