Synthese Vol. 18 : 1-4: 1968 

 -  D. Reidle Publishing Co. Holland  1968 
<br/><br/><label>Subjects--Topical Terms: </label><br/>AORIm5962:N49
<br/><br/><label>Dewey Class. No.: </label>AORIm5962:N49  / H9.18