• 7 Christianity
• 6 Civilization, Ancient
• 6 Conservation of natural resources
• 6 Economic aspects
• 6 Effect of human beings on
• 6 Natural resources
• 6 Nature
• 6 Papacy
• 6 Pollution
• 6 Social ecology
• 6 Water
• 5 Environmental aspects
• 5 Environmental geography
• 5 Environmental protection
• 5 Human ecology
• 5 Human geography
• 5 Hydrology
• 5 Landforms
• 5 Refuse and refuse disposal
• 5 Toxicology
• 5 Waste disposal
• 4 Archaeology
• 4 Population policy
• 4 Rites and ceremonies

• 21 Films Media Group
• 21 Films for the Humanities & Sciences (Firm)

• 21 English

• 4 Europe
• 3 Middle East
• 1 Africa
• 1 Africa, North
• 1 Amazon River
• 1 China
• 1 East Asia
• 1 India
• 1 Peru
• 1 South America
• 1 South Asia
• 1 United States

Limit year range