The randomness of literature reviews

Is doing a literature review as random for you as it seems to be for me? I'm doing an independent study course this fall that will result in a review of the literature related to informal scholarly communications and the changes that computer mediated communication will/may have. I did a round of searches from scratch and reading based on the results and am now chasing citations from that and conducting some more searches. I had hoped that by this time (six or seven weeks into the semester) that I'd feel more as if I was making some progress but I don't. I'm still finding new leads (and fearing that I've missed others) and reading what I can get my hands on. But here's where the randomness comes in: some of it I just plain can't get hold of, even interlibrary loan doesn't work. And so much of it seems to be 'grey literature', conference presentations, and other ephemeral type stuff. AND it's so interdisciplinary! I just found an article in a biology journal! Sigh. Maybe this is what I need to write up in my results?!