https://en.wikipedia.org/wiki/Inside_Llewyn_Davis
https://en.wikipedia.org/wiki/Dave_Van_Ronk (1936-2002)
https://www.myvideo.net.tw/details/0/47913
https://www.youtube.com/watch?v=Wa0xDq4_iT0&list=RDEMdX7PFjnlIPyZGs8XekMP8w&start_radio=1
https://www.youtube.com/watch?v=AaRTvAFIYF4&list=RDEMdX7PFjnlIPyZGs8XekMP8w&index=19 (last call)