Heber Curtis

[1942] Heber Doust Curtis, 1872-1942 ; Robert R. McMath ; PASP 54 (1942) p. 69 [lien]
[1976] Ritchey, Curtis and the Discovery of Novae in Spiral Nebulae ; M. A. Hoskin ; Journal for the History of Astronomy 7 (1976) p. 47 [lien]