Ehud Spanier, Elisha Linder, Nira Karmon, Purple Dye—Biology, Archaeology and History (University of Haifa, Center for Maritime Studies, 1980), see also Sifre, Deuteronomy 354; Shabbat 26a; Menahot 42b; Isaac Herzog, “The Dying of Purple in Ancient Israel” (University of London dissertation, 1919).
