And the books cannot be placed on more than one device, so they are not easy to share.

VOA: special.2009.09.03

So it's a different class of resource not as easy to develop, and not even recognized as something worth pursuing, say,twenty years ago."

VOA: special.2009.10.23

They act as if they are giving us charity,she says. So really it is not easy.

VOA: standard.2009.08.27