SNAC, SNAC Ark-ID: w64k35sf, läs online, läst: 9 oktober 2017.[källa från Wikidata]
kb.se
libris.kb.se
Bertalanffy, Ludwig von (1968) (på engelska). General system theory: foundations, development, applications. New York: Braziller. Libris68336 s. 39-40: “the conventional formulation of physics are, in principle, inapplicable to the living organism being open system having steady state. We may well suspect that many characteristics of living systems which are paradoxical in view of the laws of physics are a consequence of this fact.”
snaccooperative.org
SNAC, SNAC Ark-ID: w64k35sf, läs online, läst: 9 oktober 2017.[källa från Wikidata]