A-Teens are a Swedish pop music group from Stockholm. The group was formed by Niklas Berg in 1998 as an ABBA tribute group called ABBA-Teens, which was later renamed A-Teens. The band members are Marie Serneholt, Amit Paul, Dhani Lennevald, and Sara Lumholdt. The group is best known for the singles "Mamma Mia" (1999), "Upside Down" (2000) and "Floorfiller" (2002), all of which were hits worldwide. The group has been particularly successful in their home country where they have amassed eleven top 10 hit singles on the Swedish charts.