https://en.wikipedia.org/wiki/Pennsylvania_(steamboat)#Employment_of_Samuel_L._Clemens ,
http://www.beliefnet.com/columnists/dreamgates/2012/01/the-shadow-of-mark-twains-precognitive-dream.html ,
https://en.wikipedia.org/wiki/Pennsylvania_(steamboat)#Final_voyage_and_sinking June 13, 1858
https://westerntrips.blogspot.ca/2011/07/mark-twain-americas-famous-steamboat.html ,
http://tripsintohistory.com/2012/01/21/the-explosion-of-the-steamboat-pennsylvania-and-the-missing-engineer
https://www.google.ca/search?q=mark+twain+precognition+of+the+pennsylvania+riverboat+disaster&source=lnms&sa=X&ved=0ahUKEwjK68u695DWAhVB_mMKHROuCY0Q_AUICSgA&biw=1536&bih=760&dpr=1.25
MT precognition of 1858-6-13
ppat, tnor
