So here I am in ABD looking up Gospel of Peter. There is a hyperlink to it as a reference (Gos. Pet,). I right-click on it, look up what resources it links to under "reference". I get this:

In other words, were I to trust this, it would appear that I have no resource where this reference can point to.
However, I do have these resources:

The problem here is that when I run guides or look up references, I may be led to think that I do not have a text that I do, in fact, have. That's a problem. I need to know that I can trust reports and cross-referencing.