Notes on Anaxagoras and Philolaus: Course notes on these contemporaries of Socrates, interpreting their ideas as reactions to the challenge posed by Parmenides and Zeno.
Philolaus of Croton: Pythagorean and Presocratic: A 1994 evaluation by Patricia K. Curd of this book by Carl A. Huffman. From the Bryn Mawr Classical Review.
Wikipedia: Philolaus: Article incorporating information from the 1911 Britannica.