hey kazama - you should always make a reference to the original designer or the writer of a tutorial - even if you use a technique from a tutorial and make something completely different it's just common curtousy to give that somebody who taught you something the credit for it. People put a lot of effort into making free tutorials and they deserve the recognition.
that being said - don't worry too much about it - just do it right next time!
Check out the subsurfacescattering on my tongue...
<a href="https://www.reitzmachine.com">www.reitzmachine.com</a>