Books which aren't available have publisher pages. Amazon pages. Something you can link to. My pet peeve is articles which are obviously inspired by journal ar

Books which aren't available have publisher pages. Amazon pages. Something you can link to. My pet peeve is articles which are obviously inspired by journal articles but which don't even link to abstracts. Just about every journal article has a free abstract online. The important thing is to establish a chain of reference. Obviously, linking to a full-text original source is even better, but the chain of reference is incredibly valuable.