Hey guys! Thanks a lot for sharing your works here. Keep on rock 
Bob3636 - Hey man! Many thanks!!! So, yes I say for all students to make contact with conceptual artist and ask permission to use his concept.
Sometimes maybe happens some problems to find the email of the concept artist or don’t get answer.
It’s very important putting the name of the (concept artist/website link) together the main post. Just let us be fair! 
All these works are not used for commercial purposes and does not intend to take the conceptual artist credit, are just objects of study. In my opinion if everything is done with honesty and putting the credit due to the image is gratifying for the conceptual artist.