Collyns, Robin. <br/><br/>
Did spacemen colonise the earth?. 

 - [London] :  Pellican,  [1974] 
<br/><br/>Bibliography: p. 249-260. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronautics and civilization -- History.--Astronautics and civilization -- History.<br/>Civilization -- Philosophy.--Civilization -- Philosophy.