Some Connecticut Republicans said they would withhold support until a concrete proposal comes forward.

WSJ: Connecticut Weighing Driver's Licenses for Illegal Immigrants

And the introduction by the Gang of Six of a concrete proposal put forward by six members of the Senate -- three Republicans, three Democrats, representing a broad ideological spectrum in American politics -- I think is a welcome development.

WHITEHOUSE: Press Briefing

For example, PLAN NYC, the sustainability agenda for the eastern US concrete jungle, includes a proposal to ensure that all New Yorkers live within a 10-minute walk of a park.

BBC: Martha Schwartz

"We believe there are concrete results in these advances in the land reform proposal, " said Jesus Santrich.

BBC: Colombia peace talks 'in mambo rhythm', say Farc rebels

The concept refers to an innovative proposal development, considering the collective participation in the process of organizing, developing and implementing solutions to concrete problems of food, education, energy, housing, income, water, health or environment.

UNESCO: ABC, Banco do Brasil Foundation and UNESCO sign South-South cooperation for social technologies | United Nations Educational, Scientific and Cultural Organization