He had used the principle in both air and space flight.

Most of the online services use the same basic principle.

"The principle should not be used to try to avoid all risks."

A similar principle is used to create electric energy in power plants.

These four principles are still used today to evaluate effective middle school programs.

This principle is used to sort tasks into two parts.

Yet all seek to use basic physical principles to increase safety.

The school attempts to use democratic principles in and outside the classroom.

The school is designed using principles from the Danish education system.

The same principle is used to create star trail photographs.