Koukis, G. and C. Ziourkas."Slope instability phenomena in Greece: A statistical analysis." Journal Bulletin of Engineering Geology and the Environment 43/1 (April, 1991): 47-60.

Koukis, G. and C. Ziourkas."Slope instability phenomena in Greece: A statistical analysis." Journal Bulletin of Engineering Geology and the Environment 43/1 (April, 1991): 47-60.