Buchi, J. Richard and Siefkes, Dirk <br/><br/>
The monadic second order theory of countable ordinals   

 - Berlin  Springer-Verlag  1973 
 - vi, 217p. 
 - Lecture notes in Mathematics   328 .
<br/><br/> "Decidable theories-II"   
<br/><br/><label>Dewey Class. No.: </label>511.3  / B919.MS