Don’t feel ashamed to cite material which does not come from a paper, e.g., TCS.SE answers, blogposts, etc.
Many times, the best content is in academic papers — simply because academics have no incentive to write elsewhere. However, you may find that the best content is on blogposts, forums, mailing lists,… In these cases, do not be ashamed to cite them: your duty is to reference for your reader where the material is.