The relationship between the two groups has been the subject of much study.

It has been the subject of much study, research and development ever since.

At some schools, planning for a family has become a subject of study.

The study subjects reported taking the drug an average of 2.4 times a month.

These classes are a main subject of study in model theory.

Effects among people in the general population, differences with study subjects.

The study subjects certainly wanted to be thin, so what went wrong?

A major subject of study is technological development in industry.

The study subjects were 31 men between the ages of 19 and 45.

It has since been the subject of extensive study and debate.