Factors related to condomless anal intercourse between men who have sex with men: results from a European bio-behavioural survey

Nigel Sherriff, Anna-Marie Jones, Massimo Mirandola, Lorenzo Gios, Marcus Ulrich, Carrie Llewellyn, Magda Rosińska, Cinta Folch, Sonia Dias, Igor Toskin, Ivailo Alexiev, Sharon Kühlmann-Berenzon