Wittgenstein, Ludwig, 1889-1951. Philosophische Untersuchungen (Personal Name)

Guida a Wittgenstein, 2002

Wittgenstein, meaning and mind : Part II, Exegesis [section symbols] 243-427, 2019: ECIP galley (publisher's series list shows that the whole of Philosophical investigations is numbered as sections 1 to 693)

Wikipedia, viewed Jan. 23, 2019 (Wittgenstein's unfinished work, Philosophical investigations, was posthumously published in two parts; each part is a collection of remarks which in the preface he called Bemerkungen that are individually numbered sequentially; the numbering in the second part used roman numerals)