13.
Dansgaard W, Johnsen SJ, Clausen HB, Dahl-Jensen D, Gundestrup NS, Hammer CU, Hvidberg CS, Steffensen JP, Sveinbjørnsdottir AE, Jouzel J and Bond G, 1993. Evidence for general instability of past climate from a 250-kyr ice-core record. Nature 364: 218-220, DOI 10.1038/364218a0.