A trick you can do is to right click a page and click "Page Info" which should have last modified date there. Sometimes doesn't work because it's like a professional site which updates pages on a daily basis for ads or whatever.
If you can't find specific info, then just omit it in your reference.
Yes, you can go via properties and that will tell you when the page was created and last modified, plus other information. However it doesn't tell you the author of the webpage.