| APS | American Philosophical Society, Philadelphia |
| BL | British Library |
| Bodleian | Bodleian Library |
| Comte Archive | Musée d’Auguste Comte, Paris |
| CUL | Cambridge University Library |
| Harvard | Houghton Library, Harvard University |
| LSE | London School of Economics |
| NAL | V&A National Art Library |
| NLS | National Library of Scotland |
| NYP | New York Public Library |
| ONDB | Oxford Dictionary of National Biography |
| SHC | Surrey History Centre |
| TC | Trinity College, Cambridge |
| TNA | National Archives, London |
| JR | John Rylands University Library of Manchester |
| WSRO | West Sussex Record Office |
| Yale | Beinecke Library, Yale University |
