In such cases two principal factors are at work.

Circulation is one of the principal factors used to set advertising rates.

The renewed development of the market in the 1980s can be traced to three principal factors.

This waste heat is one of the principal factors that affect tube life.

It is one of the principal factors that set them apart from adult killers.

Nervous systems are one of the principal factors that limit shrinking body size.

The thesis of the first part is that environmental coincidences are the principal factor in human history.

The talks also underscore a principal factor behind the mergers, the high cost of technology.

Of these, nine countries reported air pollution as being the principal factor responsible for weakening forest health.

One of the principal factors is the reliance on coal as the main source of power.

In modern society, knowledge has replaced muscle and physical capital as the principal factor in production.

This is the principal factor that prevents its use as engine-starting batteries.

This migration was the principal factor in the settling of northern Belize.

Both cited tight labor markets as a principal factor that would constrict growth next year.

A lack of response would suggest that the high concentration of alcohol is the principal factor.

Mao believed that human consciousness is the principal factor in human history.

"The principal factor involved is risk of flight.

Indeed, the strong overseas results were the principal factor behind the record fourth-quarter results that the company reported today.

One of the principal factors in winning parole is an admission of guilt.

Failure to define, at any rate in politics, is the principal factor which keeps us in employment.

These may be the principal factors which have tended to control and limit the nature and scope of research.

Interestingly but not surprisingly, a higher proportion of men than women took occupation to be the principal factor determining class.

The clergy's civil constitution became the principal factor driving deep conflicts between clergy and Republicans.

"Beauty is the principal factor in my work.

Rain was the principal factor in a low-scoring match on a treacherous surface.