On the track of discovery :  riddles of outer space. scientists unravel mysteries. secrets of history. / 
translated by D. Skvirsky and V. Talmi. 
 - Moscow :  Progress publishers,  1964. 
 - 190 p. :  ill. ;  21 cm. 
 - Series ;  2. .
<br/><br/>313  313 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Travel.<br/>Geography.
<br/><br/><label>Dewey Class. No.: </label>910 / P943o