^G. E. Mobus & M. C. Kalton, Principles of Systems Science, 2015, New York:Springer.
^Philip M'Pherson (1974, p. 229); as cited by: Hieronymi, A. (2013), Understanding Systems Science: A Visual and Integrative Approach. Syst. Res.. دُوِي:10.1002/sres.2215. He defined systems science as "the ordered arrangement of knowledge acquired from the study of systems in the observable world, together with the application of this knowledge to the design of man-made systems."