Right let me put this straight now I understand more. I am using a method thats it I have changed the effect and the script only the method is left and even this is nothing new it's a slight twist on something very old.
Again as Tomo's been saying it's not a copyright issue. Copyright only protects the medium and the text, not the meaning of the words.
Email Dale, he knows things... He'll tell you who to credit. Credit them and you're sorted. It's nice if you get in contact with them and show them your changes and work on their idea but it's not essential from a legal point of view, only advisable from a moral one.
Yeah Dale didn't know, I don't know where the book is? I've moved that many times in last years and half and have my stuff in so many places that I don't know where it could be