Association spokesman Charles Schmidt says electronic textbooks now represent just two to three percent of sales.

VOA: special.2009.09.03

Giotto explored how to represent three dimensional space using light and shade.

VOA: special.2010.06.23

These groups represent only two to three percent of Colombia's total population, but comprise about eight percent of the more than two million internally displaced people in the country.

VOA: standard.2009.03.22