1. Ford, F.L.: Political Murder: From Tyrannicide to Terrorism. Harvard University Press, Cambridge (1987)
2. Schneider, W.: Sinn und Un-Sinn: Umwelt Sinnlich Erlebbar Gestalten in Architektur und Design. Bau-Verlag, Berlin (1957)
3. Barsalou, L.W.: Perceptual symbol systems. Behav. Brain Sci. 22(04), 577–660 (1999)
4. Helson, H., Blake, R.R., Mouton, J.S., Olmstead, J.A.: Attitudes as adjustments to stimulus, background, and residual factors. J. Abnorm. Soc. Psychol. 52(3), 314 (1956)
5. Sherif, M.: An Outline of Psychology. Sage Publications, New York (1948)