APA

Nolen S., Ekman R. & Lindqvist K. (2004). Bicycle helmet use in Sweden during the 1990s and in the future. : Increased bicycle helmet use in Sweden.

Chicago

Nolen Sixten, Ekman Robert and Lindqvist Kent. 2004. Bicycle helmet use in Sweden during the 1990s and in the future. : Increased bicycle helmet use in Sweden.

Harvard

Nolen S., Ekman R. and Lindqvist K. (2004). Bicycle helmet use in Sweden during the 1990s and in the future. : Increased bicycle helmet use in Sweden.

MLA

Nolen Sixten, Ekman Robert and Lindqvist Kent. Bicycle helmet use in Sweden during the 1990s and in the future. : Increased bicycle helmet use in Sweden. 2004.