Shit. That's the old one. Excellent adventures was a reboot. http://www.4shared.com/office/E6EdJwUxba/Nidoran_Duran_-_Solaceon_Dayca.html there's excellent adventures. I'd still recommend reading the older one.
If you're on a computer when posting, as opposed to mobile, you can use this extension: https://saucenao.com/tools/. Let's you image search from a variety of websites from a dropdown menu when right-clicking, SauceNao being one of them.
SauceNao is probably the best at finding NSFW sources. It'll give you sources on many boorus (gelbooru, e621, etc.), a bunch of japanese sites (such as pixiv), and deviant art. Doesn't cover stuff on Fur Affinity, Inkbunny, NewGrounds, or Twitter though.
https://saucenao.com/ ← You can still use it if you don't have the extension.
As for this image, SauceNao just pulls up the Gelbooru page, as that seems to be the only SauceNao-compatible site that it has been posted on. On most art pieces found on boorus, there is a source. In the column on the left, there should always be a link to the original posting of the content in the case that it's public. This image has its twitter source linked in the sidebar there.