Natural gas has been a viable source of energy in the world.

They are a viable source of income and nutrition.

The search for more economically viable sources continues in the area.

That leaves only two viable sources of support for the economy in the short term - private and government consumption.

"By being a viable alternative source it should keep the rest of the suppliers in check."

There are no other viable sources for the total number of martyrdoms in a province.

Agriculture, although small, is the most viable local source of income.

With the Internet now being a viable source for music, net labels emerge.

The only viable source, it seems to me, is from for-profit making companies.

"He seemed to think that was a viable source of information."