In fact, I saw first these pictures, that you're talking about, but I did'nt know who is their author..
They were just used in a lesson, published somewhere in the net..
So, ok - the consept is his and he's the main creator and..?
I did it just for fun, only for my pleasure.
Y'know,if you're going to basically copy a picture 'Change of Seasons' that was one of the most faved in Deviantart when he was a member,you might want to give the original artist 'Silveryn' [link] some credit in your description,seeing as he's the guy who's considered by most to have come up with that particular vectoring style about 4 years ago now.