1st appearances from the copper age. 1980 or 1981 to 1991. I believe it should start at 1980 but 1981 seems more appropriate...giving Bronze (1970 to 1980) and Copper (1981 to 1991). Bronze might end somewhere around here. 11 years each, I daresay. Either way, the books I collected as a lad as this was my beginning the hayday of collecting multiple copies as a pursuit of investing. I have submitted Many of these books on my own yet some were later replaced by better achieved grades. I love this era though sometimes wish I was 20 years older and have the same passions I had here.......what a hoot that would be.