Tephra studies proceedings of the NATO Advanced Study Institute "Tephra Studies as a Tool in Quaternary Research", held in Laugarvatn and Reykjavãik, Iceland, June 18-29, 1980 - Self, S. (Stephen) 1946-; Sparks, R. S. J. (Robert Stephen John) 1949- (NATO advanced study institutes series. Mathematical and physical sciences, 1981)