Passier, Hilde F.; Bosch, Hendrik-Jan; Nijenhuis, Ivar A.; Lourens, Lucas J.; Boettcher, Michael E.; Leenders, Anke; Sinninghe Damste, Jaap S.; de Lange, Gert J.; de Leeuw, Jan W. (1999): Sulphidic Mediterranean surface waters during Pliocene sapropel formation. Macmillan Journals, London, United Kingdom, Nature (London), 397 (6715), 146-149, georefid:1999-023330