Defining the concept of class is not an easy task.

"The first thing we did was define the concept," he said.

Researchers at the Institute also defined the concept of peak water.

Professor Williams says that the film "takes credit for first defining the concept".

There are multiple ways to define the concept of "species".

The latter defined the scientific concept and development of the institute until his death in 1964.

We define the concept of a strong generating set relative to a base.

It's like trying to define the concept of love itself objectively.

Rather, the central case method defines concepts by looking to the purpose or value of the concept.

The terms language and dialect are not easily defined concepts.