Werner, R. A. Service Facility Stable Isotope/Gas Analytics, Dr. W. A. Brand, Max Planck Institute for Biogeochemistry, Max Planck Society;
Fronza, G., Fuganti, C., Schmidt, H.-L., & Werner, R. A. (2002). The δ18O-value of the p-OH group of L-tyrosine permits the assignment of its origin to plant or animal sources. European Food Research and Technology, 215(1), 55-58.