Charles S. Underhill

• Handy Key to Your "National Geographics"
• Handy Key to Your "National Geographics" Subject and Picture Locater 13th Edition, 1915-1977
• Handy Key to Your National Geographic Subject and Picture Locator 1915 Dec 1985
• Handy Key to Your National Geographic Subject and Picture Locator, 1915-December 1983