Παρόμοια τεκμήρια

• Conserving american resources /
  ανά: Parson, Ruban L
  Έκδοση: (1964)
• Origins of American conservation /
  ανά: Clepper, Henry
  Έκδοση: (1966)
• Conservation education in american schools : twenty-ninth yearbook /
  Έκδοση: (1951)
• Higher education in the american economy /
  ανά: Daniere, Andre
  Έκδοση: (1964)
• Resources in America's future : patterns of requirements and availabilities 1960-2000 /
  ανά: Landsberg, Hans H
  Έκδοση: (1963)