Label-Free Molecular Imaging of Biological Cells and Tissues by Linear and Nonlinear Raman Spectroscopic Approaches. - Krafft, Christoph; Schmitt, Michael; Schie, Iwan W.; Cialla-May, Dana; Matthäus, Christian; Bocklitz, Thomas; Popp, Jürgen (Angewandte Chemie International Edition, 2017)