1. Oil Shale;Gavin,1924
2. “A New Structural Model of Oil Shale Kerogen”;Yen;ACS Div. Fuel Chem. Preprints,1974
3. Application of Microbiology to Energy and Environment;Yen,1975
4. “Organic-rich Shale of the United States and World Land Areas”;Duncan;Geol. Surv. Circ.,1965
5. “The Oil Possibilities of the Oil Shales of the United States”;Winchester;Federal Oil Conservation Board of the President of the United States,1928