Hock, C., Villringer, K., Mueller-Spahn, F., Wenzel, R., Heekeren, H. R., Schuh-Hofer, S., et al. (1997). Decrease in parietal cerebral hemoglobin oxygenation during performance of a verbal fluency task in patients with Alzheimer`s disease monitored by means of near infrared spectroscopy (NIRS) - correlation with simultaneous rCBF-PET measurements. Brain Research, 755, 293-303. doi:10.1016/S0006-8993(97)00122-4.