Columbia subject headings:
Plato. Parmenides.
Reasoning--Early works to 1800.
Socrates.
Zeno, of Elea.
Harvard subject headings:
One (The One in philosophy)
Plato. Parmenides.
Plato. Parmenides. Libri septimi ultima pars.
Reasoning.
Socrates.
Zeno, of Elea.
Princeton subject headings:
Plato. Parmenides.
Reasoning--Early works to 1800.
Socrates.
Zeno, of Elea