1.   Anticommunism and the constitutional order provided the principal sources of political cohesion in the new political entity.

2.   Nevertheless, many Third World countries still rely heavily on selling raw material commodities as their principal source of income.

3.   Professional pollsters have displaced precinct party chairmen as the principal source of information about what the public is thinking.

4.   Such surveys formed the basis for research for many years and still remain the principal source for some categories of data.

5.   Teaching is her principal source of income.

6.   The aim is to identify the principal aesthetic sources of the continent, both within local culture and the modern world.

7.   The annual population estimates constitute the principal source of official statistics on sub-national populations.

8.   The principal source of finance for all of this remained the record company.

9.   This is one of the two principal sources of new NEOs.