found: LCCN 55-5606: His Humboldt, 1955 (hdg.: De Terra, Helmut, 1900- )
found: LC data base, 12-27-84 (hdg.: De Terra, Helmut, 1900- ; usage: Helmut De Terra)
found: The ice age in the Indian subcontinent, 2003: t.p. (H. De. Terra)
found: Research on early man in Burma, 1943 : t.p. (Hellmut de Terra)
found: OCLC, Aug. 24, 2009 (hdgs.: De Terra, Hellmut; De Terra, Helmut; De Terra, Helmut, 1900- ; De Terra, Helmut, 1900-1981; Terra, H.; Terra, Hellmut de; Terra, Hellmut de, 1900- ; Terra, Hellmut de, 1900-1981; Terra, Helmut; Terra, Helmut d; Terra, Helmut de; Terra, Helmut de, 1900-1981; DeTerra, Hellmut; DeTerra, Helmut; usage: Helmut de Terra; Hellmut de Terra; H. de Terra; Hellmut DeTerra)
found: New York Times obituaries, via Google search on Aug. 24, 2009 : Late City Final Ed., July 24, 1981, sec. A, p. 14, column 5 : (Helmut de Terra, specialist in Pleistocene and Cenozoic geology who taught at Yale, Ohio State, Columbia and the New School, died in Bern)
De Terra, Helmut, 1900-1981
