Adviser, director and later chairman, she played an indispensable role in its success as an international theatre company.

They become very creative at discovering new enemies and bigging up their indispensable role in keeping people safe.

In democratic societies, journalism and the media play an indispensable role in educating the public and combating corruption.

In the 1970s, however, new research showed that secondary plant metabolites play an indispensable role in the survival of the plant in its environment.

The feathers of wild birds play an indispensable role in controlling pests.

It proves to be an indispensable tool for analysing the inscription of traumatic events in forms of cultural expression.

Its elegant books — illustrating the fashion for the coming seasons in clothing, art, design, and cooking — are now an indispensable tool for retailers and buyers.

Propaganda can be an indispensable tool in fostering an environment of doubt and anxiety.

It has been described as valuable, as an indispensable tool and as an old friend.

By 1985 there were more than 1,000 teacher training schools - an indispensable tool in the effort to solve the acute shortage of qualified teachers.