Heidi Samuel Klum

In 2004, Klum co-authored Heidi Klum's Body of Knowledge with Elle magazine editor Alexandra Postman. The book gives Klum's biography as well as her advice on becoming successful. Prior to that, Klum had been an occasional guest columnist for the German television network RTL's website. She wrote an essay for the German newspaper Die Zeit.
In November 2006, Klum released her debut single "Wonderland", written for a series of television advertisements for the German retailer "Douglas". Proceeds were given to a children's charity in her hometown of Bergisch Gladbach. She contributed to her husband Seal's 2007 album System, singing the duet "Wedding Day", a song that Seal wrote for their wedding.