The sources I've cited (so far) are the Module 4 exercise (McNulty Getaways) model solution and the Segal text, both for Task 4. I used footnotes. (I wouldn't put everything at the end of the assessment, because you're supposed to keep everything relevant to each task within that task's brackets. The instructions said not to put all your appendices at the very end of the doc, but to keep them with their tasks.) I mentioned ASOP 23 in Task 1 but didn't
cite it. I think if you want to cite an ASOP, just give the ASOP # and the relevant section. The general rule for FAP was that citations didn't have to follow an official format; as long as the reader can locate the thing you are citing, that's good enough. So I wouldn't stress about it.