| William Crookes Science n.d. Salted paper print, produced from a paper stencil National Museum of American History, Smithsonian Institution 1995.206.661; Schaaf 5558 LL/75622 Larry J. Schaaf, "Earth Day & Henry", Blog (21 April 2017)
foxtalbot.bodleian.ox.ac.uk/2017/04/21/earth-day-henry/
| |