"Natural resources United States." . . "Ressources naturelles." . . . . "Conservation of natural resources United States." . . "Conservation des ressources naturelles États-Unis." . . "United States" . . "United States." . "EE. UU." . . "Economic history." . . "Natural resources." . . "Estados Unidos" . . "The Conservation of Natural Resources in the United States" . . . "Conservation of our natural resources, based on Van Hise's The conservation of natural resources in the United States" . "Conservation of our natural resources, based on Van Hise's The conservation of natural resources in the United States"@en . . . . "Conservation of our natural resources : based on van Hise's: The conservation of natural resources in the United States" . . . . . . . . . . . . . . . . "Conservation of our natural resources"@en . . . "The conservation of natural resources in the United States"@en . "The conservation of natural resources in the United States" . "The Conservation of Natural Resources in the United States ... Illustrated"@en . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Conservation of Our Natural Resources. Based on Van Hise's The Conservation of Natural Resources in the United States. By Loomis Havemeyer ... editor [and others], etc"@en . . . . . . . . "Conservation of our natural resources : based on Van Hise's The conservation of natural resources in the United States"@en . . . "Conservation of our natural resources in the United States"@en . . . . . . . "The Conservation of natural resources in the United States" . . . . . . . . . "Conservation of our natural resources based on Van Hise's The conservation of natural resources in the United States"@en . . . . . . . . "Ressources naturelles États-Unis." . . "Conservation of natural resources." . . "États-Unis" . .