One method was to sell oil in one area of the country for much less than the oil was worth.

VOA: special.2010.04.25

Books and magazines told how to travel to the area and the best method of finding gold.

VOA: special.2009.02.11

The health center has a Kangaroo Clinic, a special area for teaching this method.

VOA: special.2009.05.25

He said that using the same method, scientists determined another area that was "ready" for a potentially devastating shaking - northern Chile, close to the border with Peru.

BBC: Further Chile earthquakes 'possible', say scientists

But within the euro area only France uses this method.

ECONOMIST: The numbers racket | The

Basically, it's an inventive method of wetland farming conducive to the area, whose freshwater springs and shallow waters made it an ideal place for chinampa agriculture.

BBC: Finding farms, and solitude, in Mexico City