Planetarium  a challenge for educators 

 - United Nations  New York  1992 
 - 150p. 
 - Planets 
<br/><br/><label>Nat. Bib. No.: </label>5352 
<br/><br/><label>Nat. Bib. Agency Control No.: </label>523.4 UNI 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Aeronautics & Space Science
<br/><br/><label>Universal Decimal Class. No.: </label>523.4