Utilitarianism was first published in 1861 as a series of three essays in volume 64 of Fraser’s Magazine (October: chs 1 and 2, November: chs 3 and 4, December: ch. 5). It was first published as a book in 1863. The second edition was published in 1864, and the third in 1867. The text I have used is the fourth, of 1871, the last published in Mill’s lifetime (London: Longmans, Green, Reader and Dyer). This text is also that used in the Collected Works (Mill 1961-91) and in my Oxford Philosophical Text of Utilitarianism (Mill 1997).
All self-standing references (e.g. 2.2) are to chapters and paragraphs of Utilitarianism. This is the case even when the self-standing reference is preceded by a reference with a prefix (e.g. L 1.9; cf. 2.2).
References to On Liberty and The Subjection of Women are also by chapter and paragraph, and prefixed by L and SW respectively (e.g. L 1.9). Quotations from these books are from the Collected Works (vols 18 and 21 respectively).
All other references to Mill’s writings are to the Collected Works, by volume and page number. Prefixes refer to the following works: