http://www.keithlantz.net/2011/10/rendering-a-skybox-using-a-cube-map-with-opengl-and-glsl/

http://ogldev.atspace.co.uk/www/tutorial25/tutorial25.html

http://blog.csdn.net/huangzhipeng/article/details/7957233

http://www.humus.name/index.php?page=Textures

Sky Box