Lennox, James (31 Jan 2017). "Aristotle's Biology". Plato. Stanford University. Archived from the original on 7 May 2019. Retrieved 23 March 2019. Section 2: Aristotle's Philosophy of Science
Lennox, James (31 Jan 2017). "Aristotle's Biology". Plato. Stanford University. Archived from the original on 7 May 2019. Retrieved 23 March 2019. Section 2: Aristotle's Philosophy of Science