Main characteristics and participation rate of European adolescents included in the HELENA study
Laurent Béghin*, Inge Huybrechts, German Vicente-Rodríguez, Stefaan De Henauw, Frédéric Gottrand, Marcela Gonzales-Gross, Jean Dallongeville, Michael Sjöström, Catherine Leclercq, Sabine Dietrich, Manuel Castillo, Maria Plada, Dénes Molnar, Mathilde Kersting, Chantal C Gilbert and Luis A Moreno