However some studies have used less than half this number.

Also, few studies in this area use a control group.

He pointed out that the study used as a control group other children who died, and not the general population.

The study will use blood samples already taken for other medical tests.

The study used ten to twenty people for the investigation.

It said that 18 medical studies using the drug had been approved since 2000.

Various studies have used a number of methods to study business networks.

We were told that there had to be a study using exactly the same methodology.

The study used data from a child sponsorship organization in six of its countries.

A new international study using modern data collection methods, would be a difficult, slow process.