aplanétisme
1972 / The Ritchey-Chrétien Aplanatic Telescope: Letters from George Willis Ritchey to Elihu Thomson / Harold J. Abrahams / Proceedings of the American Philosophical Society 116 (1972) p. 486 [lien]
1982 / The First Aplanatic Object Glass / J. A. Bennett / Journal for the History of Astronomy 13 (1982) p. 206 [lien]