Ultrafast photoelectron spectroscopy: Femtosecond pump-probe coincidence detection of ammonia cluster ions and electronsV. Stert, W. Radloff, C. P. Schulz and I. V. HertelEur. Phys. J. D, 5 1 (1999) 97-106DOI: https://doi.org/10.1007/s100530050234