I'm looking for a book on US paper money collecting. My father in-law has several books on coin collecting and a lot of coins he's collected over the years. He has a few older bills and silver certificates and such. He needs a book on the bills, but I can't seem to find one. I know I'm just using the wrong terminology in my search. Does anyone know of a book or two? He swears he's seen a dollar printed of people plowing a field on the History Channel.