Osterbrock, Donald E.

Combined from CaltechTHESIS advisor

• Abell, George Ogden (1957) The Distribution of Rich Clusters of Galaxies; 10.7907/99X5-ZM38
• Mathis, John Samuel (1956) The Abundance of Helium Relative to Hydrogen in the Orion Nebula; 10.7907/CB4D-4026