The principal difference is in how they are used and which direction the energy flows.

That's the principal difference between our program and the Government's.

The principal difference is that the shareholders would wind up with much less.

A principal difference lies in the cost of the equipment.

The principal difference between the two types was the engine.

Beyond those points, though, the principal difference between the two plans is money.

This is the principal difference between a dog and a man.

Yet for all they had in common, the principal difference between the two was vast and paramount.

The principal difference was that the new company, like many others in the furniture business, sold on credit.

The principal difference between us is the level of agricultural development.