Stark, R., Schienle, A., Walter, B., Kirsch, P., Sammer, G., Ott, U., Blecker, C., & Vaitl, D. (2003). Hemodynamic responses to fear and disgust-inducing pictures: an fMRI study. International Journal of Psychophysiology : Official Journal of the International Organization of Psychophysiology, 50(3), 225–234. https://doi.org/10.1016/s0167-8760(03)00169-7