Home › Authors › H. P. Greenwald 👤 H. P. Greenwald b. 1893 ยท 2 books Books by H. P. Greenwald Experiments to determine the m Experiments to determine the minimum amount of coal-dust required for propagation of a mine explosion 1931 Coal-dust explosibility factor Coal-dust explosibility factors indicated by experimental mine investigations 1911 to 1929 1929