Freeman Bibliographical Database
| Identifier: | F3379 |
| Date: | 1908 |
| Concise reference: | Darwin, C. R. 1908. [Letters to Herbert Spencer and J. D. Hooker, 1858, 1860, 1866, 1867]. In David Duncan, The life and letters of Herbert Spencer. London, pp. 87, 98, 125, 150. |