Workshop on Planetary nebulae (Czechoslovakia, 1967) <br/><br/>
Planetary nebulae   
ed. by D.E. Osterbrock, C.R. O'Dell. 
 - Holland  D.Reidel Publishing Company  1968 
 - xv, 469p. 
 - International astronomical union symposium No.34 .
<br/><br/><label>Dewey Class. No.: </label>521.582  / N68