"The Theology of Arithmetic". Translated by Robin Waterfield in "The Theology of Arithmetic: On the Mystical, Mathematical and Cosmological Symbolism of the First Ten Numbers", 1988.
James Boswell, Samuel Johnson (1824). “The Life of Samuel Johnson, LL. D., Comprehending an Account of His Studies, and Numerous Works, in Chronological Order: A Series of His Epistolary Correspondence and Conversations with Many Eminent Persons; and Various Original Pieces of His Composition, Never Before Published; the Whole Exhibiting a View of Literature and Literary Men in Great Britain, for Near Half a Century During which He Flourished”, p.6