Pulgram, Ernst.
Introduction to the spectrography of speech /
Ernst Pulgram 
. - 2nd printing 
. - The Hague : Mouton & Co,  1964 
. - 174 p.  ill., schem.  23 cm. 
 - (Janua linguarum : studia memoria Nicolai van Wijk dedicata  ; nr. 7 )
<br/>К.: Бібліогр. : c. 171-174