Millions more used buses and cars in what is believed to be the world's biggest annual human migration.

VOA: standard.2010.02.14

The president said the United States is prepared to engage in a dialogue with the Cuban government that includes human rights, free speech,democratic reform, migration,and economic issues.

VOA: standard.2009.04.17

In 2011, as a result of a two-day workshop on Internal Migration and Human Development, UNESCO and UNICEF launched the Internal Migration in India Initiative (IMII) to support the social inclusion of migrants in the economic, social, political and cultural life of the country, using a three-legged approach combining research, policy and advocacy.

UNESCO: All Events | United Nations Educational, Scientific and Cultural Organization

In a study of 127 developing countries in 2009, the prospect of migration boosted human capital, rather than draining it.

ECONOMIST: The medical workforce

While hundreds of studies around the world have linked climate change to phenomena including the increased frequency and intensity of hurricanes and other storms, changing rainfall patterns, drought, coastal flooding, changing disease patterns and the migration of human populations.

CNN: Environmentalists hope UN talks tough on climate change