• 7 Biodiversity
• 7 Biotic communities
• 7 Ecology
• 7 Water
• 6 Cultural geography
• 6 Hydrology
• 6 Natural resources
• 6 Rivers
• 6 Social ecology
• 6 Voyages and travels
• 4 Air
• 4 Climatic changes
• 4 Ecosystem management
• 4 Marine biology
• 4 Marine ecology
• 4 Marine organisms
• 4 Pollution
• 3 Biosphere
• 2 Tara (Yacht)
• 1 Bedouins
• 1 Biodiversity conservation
• 1 Deserts
• 1 Marine biodiversity

• 13 Films Media Group
• 13 Films for the Humanities & Sciences (Firm)
• 6 Looking Glass Pictures
• 4 Ampersand Film & Video Tape Productions
• 3 Parthenon Entertainment (Firm)

• 13 English

• 3 Arabian Peninsula
• 1 Bicol River (Philippines)
• 1 Cauvery River (India)
• 1 Mekong River
• 1 Red River Delta (Vietnam)
• 1 Red Sea
• 1 Tonle Sap (Cambodia : Lake)
• 1 Zuo River (China)

Limit year range