Also calls upon States to identify best practices and to take all appropriate national, bilateral and multilateral measures, to allocate resources for the development of long-term policies, programmes and practices, to collect comprehensive and disaggregated gender-specific data and, while reaffirming the right of children, including adolescents, to express themselves freely, to facilitate the participation of child victims of sexual exploitation, taking into account their age and maturity, in the development of strategies to end the sale of children and their organs, sexual exploitation and abuse, including the use of children for pornography, prostitution and acts of paedophilia, and to combat existing markets;