Richardson C.a et al., A luminescence chronology for loess deposition in Washington State and Oregon, USA, Zeitschrift fur Geomorphologie. Supplementband Zeitschrift fur Geomorphologie. Supplement;Zeitschrift fur Geomorphologie. Supplementary issue Annals of geomorphology. Supplement;Annales de geomorphologie. Supplement, 116, 1999, pp. 77-95