APA (7th ed.) Citation

Luhmann, N., Baecker, D., & Gilgen, P. (2013). Introduction to systems theory. Polity Press.

Chicago Style (17th ed.) Citation

Luhmann, Niklas, Dirk Baecker, and Peter Gilgen. Introduction to Systems Theory. Cambridge, UK ; Malden, Mass.: Polity Press, 2013.

MLA (9th ed.) Citation

Luhmann, Niklas, et al. Introduction to Systems Theory. Polity Press, 2013.