I've been designing models and would like to sell them as kits and as completed models. Most of my design work is of the support structure for spheres which I then use to model planets. For the skin I've been icosahedral maps designed as card models by Calvin J Hamilton. These have no support structure. http://solarviews.com/eng/ico.htm I find a lack of support structure for cardmodels to be unsatisfying because there's nothing solid to press against when glueing joints. How do I handle the copyright issue? I'd like to credit Calvin Hamilton and compensate him by either paying or sending people to his website. I can't just send people to the website for the skins because they take some modification in order to work over a sphere. I'm going to have to get the images of moons and planets from some place regardless of where that is. And that means I need to know how to give credit and compensation for use of those images.