AUTHOR=Pichini Simona , Pacifici Roberta , Marinelli Enrico , Busardò Francesco P. TITLE=European Drug Users at Risk from Illicit Fentanyls Mix JOURNAL=Frontiers in Pharmacology VOLUME=8 YEAR=2017 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2017.00785 DOI=10.3389/fphar.2017.00785 ISSN=1663-9812