Schlinger, Evert I. <br/><br/>
A Revision of the Acrocerid Flies of the Genus Pialea Erichson with a Discussion of their Sexual Dimorphism (diptera) 

 - Washington :   Smithsonian Institution,   1956. 
 - 359 p. ;   18 cm. 
 - United States National Museum ;   3373 .