Extreme conditions in the molecular gas of lensed star-forming galaxies at z ~3 Paola Andreani, Edwin Retana-Montenegro, Zhi-Yu Zhang, Padelis Papadopoulos, Chentao Yang and Simona Vegetti A&A, 615 (2018) A142 Published online: 27 July 2018 DOI: 10.1051/0004-6361/201732560