Merriam-Webster, 1995
Buku Referensi
Meriam-Webster, Incoporate, 1995
Buku Referensi
edited by Joseph T. Shipley
Philosophical Library, 1946
Buku Referensi
edited by Joseph T. Shipley
Philosophical Library, 1946
Buku Referensi
Slethaug, Gordon, author
Bloomsbury, 2014
Buku Teks