TY - JOUR A1 - Kneipp, Janina A1 - Kneipp, H. A1 - Kneipp, K. T1 - Two-photon vibrational spectroscopy for biosciences based on surface-enhanced hyper-Raman scattering JF - Proceedings of the national academy of sciences of the United States of America : PNAS PY - 2006 SN - 0027-8424 SN - 1091-6490 VL - 103 IS - 46 SP - 17149 EP - 17153 PB - National Academy of Sciences CY - Washington, DC AN - OPUS4-13934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -