Epictetus, Marcus Aurelius, Lucius Annaeus Seneca (2016). “Stoic Six Pack: Meditations of Marcus Aurelius, Golden Sayings, Fragments and Discourses of Epictetus, Letters from a Stoic and The Enchiridion”, p.110, Enhanced Media Publishing
Francis Quarles (1844). “Enchiridion Institutions, Essays and Maxims, political, moral & divine. Divided into four centuries. By Francis Quarles”, p.29