Osteospermum - Wikipedia
   An account of the genus Osteospermum, with a list of species and advice on cultivation.
   http://en.wikipedia.org/wiki/Osteospermum

PBSWiki - Ornithogalum
   Notes on the cultivation of the different groups within the genus Ornithogalum, with photographs of various species and hybrids uploaded by members of the Pacific Bulb Society.
   http://www.pacificbulbsociety.org/pbswiki/index.php/Ornithogalum