Glancing angle X-ray study of crystallization of amorphous Ge at the Ge-Al interface, Mat. Res. Soc. Symp. Proc., Vol 202, Evolution of Thin Films and Surface Microstructure, edited by C.V. Thompson, T.Y. Tsao, D.J. Srolovitz (MRS, Pittsburgh 1990); SM Heald, JKD Jayanetti, RC Budhani