Vanguard raised its prices over time but still remained an economical source of hardcover books.

Agriculture is the primary economical source of livelihood.

The Economy New windmills are ready to take their place as an economical and important source of the nation's energy.

In everyday use samovars were an economical permanent source of hot water in older times.

The real sticking point is finding economical sources for hydrogen.

If and when California makes the switch to ethanol, we have not yet determined the most economical source of that fuel additive.

The most convenient and economical source of concrete is a ready-mix dealer.

Agriculture and Cashew nut are the main economical source of this area.

Efficient and economical alternative sources of energy will take time to develop.

Water was no longer an economical source of power and many mills were abandoned.