National Research Council of the National Academy of Sciences1939American geophysical union transactions of 1939
pt. 4 . Twentieth annual meeting April 26 to 29, 1939 Washington, D.C.
National Research Council of the National Academy of Sciences1939American geophysical union transactions of 1939
pt. 3 . Twentieth annual meeting April 26 to 29, 1939 Washington, D.C.
National Research Council of the National Academy of Sciences1939American geophysical union transactions of 1939
pt. 2 . Twentieth annual meeting April 26 to 29, 1939 Washington, D.C.