"Astronomija Pouk Zborniki." . . . . . . . . . "Planetarium, a challenge for educators : a guidebook published by the United Nations for International Space Year" . . "Handbooks and manuals"@en . "Handbooks and manuals" . . . . . . . . . "Planetarium a challenge for educators : a guidebook published by the United Nations for International Space Year"@en . . . . . . . . . "Planetarium : a challenge for educators : a guidebook published by the United Nations for international space year" . . . . . . . "Planetarium : a challenge for educators : a guidebook published by the United Nations for International Space Year" . "Planetarium : a challenge for educators : a guidebook published by the United Nations for International Space Year"@en . "Planetarium, a challenge for educators a guidebook published by the United Nations for International Space Year"@en . . . "SCIENTIFIC SOCIETIES." . . "ASTRONOMY." . . "Planetaria." . . "DIRECTORIES." . . "SCIENCE EDUCATION." . . "OBSERVATORIES." . . "United Nations. Department of Political Affairs. Office for Outer Space" . . "TEACHING METHODS." . . . . "Planetariji Zborniki." . .