Note 6 — PART I. CLASSIFICATION OF NEBULAE
Reading edition
“A General Study of Diffuse Galactic Nebulae,” Mt. Wilson Contr., No. 241; Astrophysical Journal, 56, 162, 1922.
Reading edition
“A General Study of Diffuse Galactic Nebulae,” Mt. Wilson Contr., No. 241; Astrophysical Journal, 56, 162, 1922.