5 & 7 (getting in touch with the researcher, via website or email) have been the most successful for me, for hard-to-get papers. I'm not certain about this, bu

5 & 7 (getting in touch with the researcher, via website or email) have been the most successful for me, for hard-to-get papers. I'm not certain about this, but I believe that authors maintain personal redistribution rights in many cases, making the whole thing above-board.