Direct observation of the conical intersection in cis-trans photoisomerization of rhodopsin - Polli, D; Manzoni, C; Brida, D; Cerullo, G; Altoe, P; Tomasello, G; Orlandi, G; Garavelli, M; Weingart, O; Kukura, P; Spillane, K; Mathies, R (Optics InfoBase Conference Papers, 2009)