We will try to ignore the often-repeated "everything in everything," which if taken literally leads to an infinite regress. We hope that Anaxagoras' theory of the composition of matter can be established by first examining his more straightforward and conventional statements; then, perhaps, the paradox will take care of itself.
Sider, David, "Anaxagoras on the Composition of Matter" (1975). The Society for Ancient Greek Philosophy Newsletter. 72.