Iggers, Georg G. (1959). "Further Remarks about Early Uses of the Term "Social Science"". Journal of the History of Ideas. 20 (3): 433–436. doi:10.2307/2708121. JSTOR2708121.
Iberall, Arthur (1984) [Presented at Annual Conference of the International Society for the Comparative Study of Civilizations (ISCSC), Syracuse, May 1980]. "Contributions to a Physical Science for the Study of Civilizations". Journal of Social and Biological Structures. 7 (3): 259–283. doi:10.1016/S0140-1750(84)80037-8.
Iggers, Georg G. (1959). "Further Remarks about Early Uses of the Term "Social Science"". Journal of the History of Ideas. 20 (3): 433–436. doi:10.2307/2708121. JSTOR2708121.
Duncan, Stewart (2021), "Thomas Hobbes", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Spring 2021 ed.), Metaphysics Research Lab, Stanford University, retrieved 2021-02-24