Gold Producers Handbook 1991, Sydney (Australia): Australian Stock Exchange Limited, (1991), pp189 inc charts.
This large paperback was bought in 1992 at a high price from Times The Bookshop downtown.
A long way back in 1991, the market price of gold was about the same as the price of platinum. It was a golden opportunity back then for anyone to exchange all his or her gold into platinum and becomes rich by now 'coz the price of platinum is more than twice the price of gold nowadays.
It's easy to mention this missed opportunity on hindsight.