Phosphorites and black shales : an International German - Israeli Conference ; held at Israel Academy of Sciences and Humanities, Jerusalem, September 1 - 5, 1991 ; [program and abstracts] - Nathan, Yaacov (Hrsg.); Gentner Symposium on Geoscience (1 : 1991 : Yerûšālayim) (Geological Survey of Israel, 1991)