As a whole the natural resources of the region have not been studied extensively.

Better details are available for the more extensively studied southern population.

The other methods are all being studied and developed extensively.

Although extensively studied by various groups, such an idea has not yet been implemented.

Ruins here have not been extensively studied but cover more than 700 years of history.

It has been extensively studied since its publication in 1905.

He has studied and reported extensively on water resource issues in Georgia since 1994.

Religion is among the factors that have been extensively studied.

The other agents in this series have not been studied extensively and information about them is limited.

What children themselves prefer appears not to have been studied extensively.