Harrison, Edward Robert. <br/><br/>
Darkness at night :  a riddle of the universe / 
Edward Harrison. 
 - Cambridge, Mass. :  Harvard University Press,  1987. 
 - 293 p. :  ill. 
<br/><br/><label>ISBN: </label>0674192710 
<br/><br/><label>LCCN: </label>90035076     
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy--History.<br/>Cosmology--History.<br/>Astrophysics--History.