Volcanic ash influence and characterization of soils on the eastern plain of the Barisan Range between Sitiung Kota Baru and Bangko, Sumatra - Subagjo, Hardjosubroto (Ann Arbor, Mich. : University Microfilms International, 1989)
Thesis (Ph.D.) - North Carolina State University, 1988
Keywords: Volcanic ash, tuff, etc. -- Indonesia; Soils -- Indonesia