• 21 Videos, Slides, Films

• 21 Physical sciences
• 9 Solar system
• 6 Exploration
• 6 Galaxies
• 6 Outer space
• 6 Space
• 6 Space flight
• 6 Stars
• 3 Physics
• 2 Sound
• 2 Sound-waves
• 2 Wave theory of light
• 2 Waves
• 1 Biography
• 1 Explorers
• 1 History
• 1 International relations
• 1 Inventors
• 1 Scientists
• 1 War
• 1 World history
• 1 World politics

• 21 Infobase

• 21 English

• 1 United States

• 21 Internet videos
• 20 Video recordings for the hearing impaired

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