Williams, H. (1948). The ancient volcanoes of Oregon. Oregon State System of Higher Education.
Cita Chicago Style (17a ed.)Williams, Howel. The Ancient Volcanoes of Oregon. Eugene: Oregon State System of Higher Education, 1948.
Cita MLA (8a ed.)Williams, Howel. The Ancient Volcanoes of Oregon. Oregon State System of Higher Education, 1948.
Precaución: Estas citas no son 100% exactas.