Nielsen is a global marketing and advertising research company headquartered in Lower Manhattan, New York City. Nielsen is active in over 100 countries, and employs some 32,000 people worldwide. Total revenues amounted to $5.1 billion in 2010.

Nielsen is a publicly held global information and media company, and is one of the world's leading suppliers of marketing information (Nielsen Consumer, formerly ACNielsen), media information and TV ratings (Nielsen Media Research), online intelligence (Nielsen Online) and mobile measurement (Nielsen Mobile). On January 25, 2011 the company issued an IPO raising $1.6 billion in the biggest private equity-backed U.S. IPO since 2006.David L. Calhoun is Nielsen's Chief Executive Officer. Calhoun came to Nielsen in 2006 from General Electric. Susan D. Whiting is the Executive Vice President of Nielsen and Chairman of Nielsen Media Research. Whiting has been with Nielsen since 1978 and was named one of the 100 Most Influential Women in New York City business by Crain's New York Business in 2007.

Abū ʿUbayd ʿAbd Allāh ibn ʿAbd al-ʿAzīz al-Bakrī, or simply Al-Bakri (Arabic: أبو عبيد عبدالله بن عبد العزيز البكري‎) (c. 1014–1094) was an Andalusian-Arab geographer and historian.

Al-Bakri was born in Huelva, the son of the sovereign of the short lived principality of Huelva. When his father was deposed by al-Mu'tadid he moved to Córdoba where he studied with the geographer al-Udri and the historian Ibn Hayyan. He spent his entire life in Al-Andalus, most of it in Seville and Almeria. He never travelled to the locations of which he wrote.

Al-Bakri wrote about Europe, North Africa, and the Arabian peninsula. Only two of his works have survived. His Mu'jam mā ista'jam contains a list of place names mostly within the Arabian peninsular with an introduction giving the geographical background. His most important work is his Kitāb al-Masālik wa-al-Mamālik ("Book of Highways and of Kingdoms"). This was composed in 1068, based on literature and the reports of merchants and travellers, including Muhammad ibn Yusuf al-Warraq (904-973) and Abraham ben Jacob. It is one of most important sources for the history of West Africa and gives crucial information on the Ghana Empire, the Almoravid dynasty and the trans Saharan trade. Although the material borrowed from Yusuf al-Warraq dated from the 10th century, he also included information on events that occurred close to the time that he wrote.