1. THE LABORATORY TESTING OF ALUMINOUS REFRACTORIES1
2. Jefferson Middleton , Occurrence of High Alumina Clays, Mineral Resources of the United States, 1918 , Part 2, 909 -10 ; also U. S. Geol. Survey, 1918 .
3. Missouri Bureau of Geology and Mines Biennial Report , Occurrence and Properties of Diaspor Clays of Missouri , pages 17-20, State Geologist, Fiftieth General Assembly, 1919 .