Sexual behaviour among young Danes aged 15–29 years: a cross-sectional study of core indicators
Marianne Johansson Jørgensen, Helle Terkildsen Maindal, Kaj Sparle Christensen, Frede Olesen, Berit Andersen
Sexually Transmitted Infections May 2015, 91 (3) 171-177; DOI: 10.1136/sextrans-2014-051814