Tlig, S. (1991): Rare earth element redistribution and fractionation during secondary mineral formation; examples from reef carbonate karst (Jebel Stah, Tunisia) and from oceanic basalts (Site 417A, northern Atlantic). Pergamon, London-New York, International, Journal of African Earth Sciences and the Middle East, 13 (2), 173-182, georefid:1995-018882