Hartman, C. G <br/><br/>
Emphasizing and connecting particles in the thirteen principal upanishads 

 - Helsinki :   Suomalainen Tiedeakatemia,   1966. 
 - 180 p. ;   20 cm. 
 - Annales Academiae Scientiarum Fennicae. Ser. B. ;   t. 143,2 .