1. Under ice mining techniques;Abel;U.S. Army Cold Regions Res. Engineering Lab. Tech. Rept. 72,1961
2. Ice tunnel closure phenomena;Abel;U.S. Army Cold Regions Res. Engineering Lab. Tech. Rept. 74,1961
3. The solubility of amorphous silica in water;Alexander;J. Phys. Chem.,1954
4. Kommission Reinhaltung der Luft,1961