Sacks, Gerald E. <br/><br/>
Degrees of unsolvability / 
by Gerald E. Sacks 
 - 2nd ed. 
 - Princeton, N.J. :  Thea250 University Press,  1966 
 - ix, 174 p. ;  24 cm. 
 - Annals of mathematics studies ;  55 .
<br/><br/>Bibliography: p. 173-175 
<br/><br/><label>ISBN: </label> USD 6.00 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Recursive functions<br/>Unsolvability (Mathematical logic)
<br/><br/><label>Dewey Class. No.: </label>517.5