"Hydrogen and Smoke: A Survey of Lighter-Than-Air Flight in South Dakota prior to World War I"https://sdshspress.com/journal/south-dakota-history-18-3/hydrogen-and-smoke-a-survey-of-lighter-than-air-flight-in-south-dakota-prior-to-world-war-ihttps://sdshspress.com/@@site-logo/sdshp-logo.jpg
"Hydrogen and Smoke: A Survey of Lighter-Than-Air Flight in South Dakota prior to World War I"